Is there an updated team building guide for LRB5+?

[Fat_Emrys]

I've had an idea for (yet another) alternative human team and want to check the concept and pricing before proposing it as a house rule team for our league. It's based on the current LRB humans with some skill swaps and I'm conscious that new skills aren't covered by the old LRB4(?) formula I found (at http://www.blood-bowl.net/NewBBTeamBuildingGuide.html).

My idea so far is:

0-16 Linemen 6338 50K G-ASP
0-4 Blockers 7337 Fend, Side-step 90K GA-SP (based on Catchers: -MV, +ST, swapped skills for +20K)
0-2 Runners 6338 Dump-off, Sure Hands 70K GP-AS (based on Throwers: swapped Pass for Dump-off)
0-4 Tacklers 7338 Tackle, Wrestle 100K GS-AP (based on Blitzers: swapped Block for Wrackle for +10K)
Rerolls 50K

with no big guy available.

It's very much a running, rugby-like team with the emphasis on getting the opposition on the floor to free up running lanes rather than hurting them.

My questions are, then:

Is this a viable, over-powered or under-powered roster?

Are Dump-off (on AG3), Tackle, Wrestle, Fend and Side-step all 20,000gp skills?

and - as a bonus question:

How much would giving Mutation access be worth, either on a normal skill roll or a double?