I'm pretty motivated to get my 7s league and wanted to ask around for advice on some house rules. The general rules are as minimalistic as possible - it's basically the normal Blood Bowl 7s pitch but with Street Bowl walls.
But something rather specific I would find logical and wanted to try out is the following:
Chainsaw-wielding Referee
If a player would normally be ejected for a foul, leave him on the pitch and make an immediate injury roll for the fouling player instead. No armour roll is required. It still counts as a turnover.
Secret Weapons
At the start of any drive when setting up his players a coach may declare that his team brought a secret weapon on the field (if available through Inducements or otherwise).
Declare which player uses the Secret Weapon (and preferably keep a relevant miniature or counter nearby). Depending on the Secret Weapon used, the player gains specific skills for the duration of the drive.
After the drive ends the player suffers an injury roll (unless a Bribe is used successfully or the player already left the pitch due to a KO or casualty result) and the Secret Weapon is lost (unless a Bribe is used successfully). A Bribe may always be used to keep a Secret Weapon available, even if the player is already KO or injured.
The Dwarven Deathroller is an exception and will be ejected as normally from the game in addition to suffering the injury roll (unless a Bribe is used successfully, in which case both effects don’t take place).
Goblin teams may always pick up to 3 Secret Weapons as free Inducements before every match, irrelevant of Team Value, in addition to any other Inducements.
Reasonings are as follows:
1) Basically any team has chainsaws or other stuff available through star players, so I see no 'critical balance mistake here'.
2) Due to the reduced player numbers of 7s, Secret Weapons can be managed better and more flexible.
3) It should all in all be a small boost to goblins - they do not suffer all the ejections and are never forced to put their secret weapons on the field. Yes, they might suffer more injuries - but then again they won't lose as many players for the match.
4) The general injury roll for fouling is imo a good way to give a slight boost and a bigger drawback at the same time. The turnover stays and in the quick 7s games a stunned result is also a strong factor. But it makes fouling a bit less of a 'dick'-move, since the referee will chop the occasional head off.
5) The few unbalanced combination (only thing i can really think of is an elf with bombs) should be counteracted by the price of suffering an injury roll on that elite player.
6) There are already Special Play Cards that do this (e.g. Chainsaw).
Thanks for reading through it, would you give me advice if I am overlooking something critical here? Especially veteran goblin coaches

As I see it (not been playtested yet) it should be more fun for goblin coaches, and also more 'logical' when thinking about the background.
Greetings!