Note, that I always write two versions, the underlined parts are the simple text (read only those) while the whole text is the “jockstrap” version, which is more technical than beautiful (but we love it anyway

Chainsaw (Extraordinary): When blocking (not when blocked) the chainsaw player has always the same strength as his opponent (before assists and modifiers) (may have to reduce his ST). And adds +3 to any armour roll made (for an opponent knocked down by this player) during a block, (no matter if blocking or blocked), (a) foul action (undertaken by this player) or (the armour roll) when knocked down himself for any reason (which also applies when a prone/stunned chainsaw is “knocked down” by bombs, Ball & Chain or Throw Team-mate (i.e. a player landing on him).) (A chainsaw does not have to make an armour roll when placed prone/stunned). (May be used with Diabolic, Enforcer, Horns, Mighty Blow, Multiple Block and in the last case with Dauntless). (May not be used with Claw, Piling On, Stab or Ball & Chain). (As by default the use of Chainsaw is optional, except for the +3 armour roll penalty when knocked down himself.)
This makes Chainsaw a block skill. The best part about it is that Chainsaw players can improve meaningful now (Block, Tackle, Frenzy etc.) and collect SPP like any other player (same block system and chances. It's comparable to a player starting with MB, at least CAS wise).
If you read all the mumbo-jumbo you'll notice a chainsaw can be combined with Mighty Blow. That used to be OK (at one point a chainsaw would become less dangerous than MB/PO) and allowing it to get back at the top of the pack was fine (after all it should be the most devastating skill in the game.) However, with PO removed from the game this isn't true any more. MB/Claw does perform better than a Chainsaw but not by much. So if you don't allow PO, you may also not allow a Chainsaw player to use MB. Your call.
EDIT: But it should be noted that a chainsaw using MB with a 56% block chance is similar to the CRP version that had a 83% chance to cause an armour roll. But it still can be argued either way.
Stab (Extraordinary): (When using Stab) the player blocks (an opponent) with 1D only (ignoring any assists, modifications (Horns and Multiple Block) (and) difference in ST), and (may ignore) skull results. (All other block rules do apply (though), and the Stab player will suffer a TO when knocked down on a Both Down result) (unless prevented by Block or Wrestle). Any subsequent armour roll (of a Stab block knocking down an opponent) may be re-rolled. (May not be used when blocked or in conjunction with Claw, Piling On, Chainsaw or Ball & Chain). During a blitz action the player may not continue moving after using Stab (this does not prevent the use of Frenzy or following up). (Stab is used instead of Dauntless and may not replace a failed Dauntless roll).
I'm not really happy with this design (not as elegant, and potentially broken), but I thought Stab really needs to improve from a “Snotling-poker” to an “Assassin skill”. Same as Chainsaw it is now also a block skill and can improve (i.e. integrated into the block system). And, again, it can be combined with MB, which in this case may be kept, except that in a PO free environment it would become the best damage skill (slightly above MB/Claw and Chainsaw). Without MB it only outperforms Claw (at least vs AV8 or lower). However, this does not factor in that this Stab version has a reduced knock down chance (only 1D blocks) compared to normal blocks (using 2D), which does balance comparisons between Stab/MB and MB somewhat. In fact, Block/Stab/MB with 1D (50%) & Block/MB with 2D (75%) are fairly even. So allowing Stab to use MB isn't that much of an issue.
And last, but not, well... Blunderbuss. This is not an important redesign, but I thought an unique skill, is better than using HMP. The following Blunderbuss version is basically a short cut to becoming a decent Thrower (on long distances). But a steadily improved Thrower (picking up all the skills) and Elves will outperform Blunderbuss eventually. This is basically a skill for teams who have no thrower, don't want to build one, but don't mind slapping it on one of their players (basically its an accurate version of HMP with less range). Note that it may need Pass (or a team re-roll) to show potential.
Some teams have developed rather drastic tactics to make up for their inability to pass the ball. One of the more insane, but nonetheless brilliant ideas, was to use gunpowder weapons to fire the ball downfield. The only thing people argue about is, if the original intention was to throw a pass, or to kill the useless receiver.
Blunderbuss/Bazooka (Extraordinary): (If used) The player makes any pass (of the ball only) on an unmodified roll of 4+ (no matter what the player's AG or modifications) (including weather and Disturbing Presence). (but) (A Blizzard may (still) not be ignored) (nor does it exclude Flash). (A Blunderbuss only ever fumbles on a natural one), (and) (The use of this skill may be announced after the roll). (Blunderbuss is a pass skill and works within a normal pass action, i.e. it is this turn's pass action, may move first, uses the range ruler, may be intercepted and may be used with Safe Throw, Pass, Pro, Weathered and Dump-off). (Blunderbuss may not be used with bombs, team-mates, spells or flamethrowers.)
And, last, but not least (truly), the SW skill. Imo the automatic send-off really was a flat-rate version only used to keep things simple at the time.
Secret Weapon (Extraordinary): At the end of each drive the player has played in (at any point), roll 3D6. If the result is below the player's salary the player is ejected and misses the rest of the match. (A 3 is always an ejection). (Can't be re-rolled.) (For convenience, you may roll the moment the player is removed for any reason (Ref-killer may be used depending on the players status at the time of removal)). (The order of status-rolls is: Apothecary/Regeneration, Secret Weapon, Bribe, Ref-killer, recovery rolls for KO). (Players with Secret Weapon must never be fielded during a kick-off, even when it means fielding less than 11 players.)
EDIT: I forgot, but if using the 3D6 idea you have to adjust the salary of SW players a little (duh).
That's Goblin Bombardier 40.000 (0,5% ejection chance), Looney 50.000 (1,9%), Fanatic 90.000 (25,9%), Deathroller 160.000 (95,4%).
Bomber Dribblesnot 90.000 (25,9%), Nobbla Blackwart 100.000 (37,5%), Boomer Eziasson 110.000 (50%), Ugroth Bolgrot, Flint Churnblade, Hack Enslash all 3: 120.000 (62,5%), Max Spleenripper, Helmut Wulf, Fezglitch all 3: 130.000 (74,1%), Fungus the Loon 140.000 (83,8%).
Feel free to adjust to your own liking.
EDIT II: This is getting embarrassing, but I just realised that all these cost adjustments are the costs of my house-rules and redesigned players

For the most part it seems OK, but the CRP players may need a bit more attention, or need to be evaluated differently. I tried to get into my 5 year old documents, to check if I have a good update for CRP only, but I can not figure it out that easily any more. It's too long ago. Seems incomplete, too. Is that mustard? God, I hope it's mustard.
However, the cost suggested above are not that terrible (they should work). But you may need some more adjustments: The blunderbuss players (Barik and Zzharg) should replace HMP & Strong Arm with Blunderbuss. You may need to give the Stab players the Block or Wrestle skill as otherwise Stab won't work so well. That's Horkon (Block), Skitter (Wrestle) and Rashnak (Block) (& you may consider to replace Rashnak's Dodge with Frenzy). Not sure about the costs, star-player costs are a bit irregular, and Blodge should improve them, then again they all have AV7 and/or ST2, so it may be OK as it is. If you disagree, bump up the costs of Horkon & Skitter by 10k or 20k (i.e. it's not that big of a deal really, but don't tell anyone I said that

I also redesigned the chainsaws, as they now improve with skills like Block, Mighty Blow, Tackle, Frenzy, and do a bit poorly without them, at least compared to the CRP version. You may either change them yourself, or use: Ugroth (add Frenzy & Juggernaut), Flint (Tackle), Hack (Thick Skull (and 110k?)), Max (MB), Wulf (MB), or reduce the costs listed above by 10k (but Nobbla) or leave it as it is (which should be fine, too, actually).
I hope that's all now.