I don't really think it needs a ton of changes. Sniper is fine imo and does what it needs to do. Rememeber when y'all were saying "Waah German sniper is useless because 2 man soviet sniper always beats him it doesn't matter if cloak isn't as good?" Dullahan remembers. Penals with flamers are a really strong unit due to their squad count size and this really shouldn't be underestimated. (The SVT is still pretty solid too)
The biggest problem with Penals right now is satchel charge is a dud.
I wouldn't mind if Penals got Oorah or something though.
They have Oorah, and cons out scale them quite easily flames or not. The satchel is a victim of the explosives effects on buildings changes, where before 10 muni infiltration grenades were bringing down houses. Buffing the satchel alone will leave T1 right where it is, don't do it. Needs some flavour. Even the tiny 45mm AT peashooter to tide you over to T3 would be something as your completely arse in the wind to vehicles.