Return of Reckoning

Used to play engi back in live and is my fav class by far. I always liked rifle spec even of how meh it was back in live
My questions are:

1) Does weapon damage affect the damage of gun blast and snipe? If so what is the high dmg weapon (with weapon skill ) i should be going for?

2) Does adding more points in rifle mastery add damage to snipe and gun blast?

Thanks for reading

Yes and yes

Speaking of weapons - there are no good rifles in PvE (gunbad or crypts and tunnels). Maybe there is one in Bastion Stairs but I haven't done it with my engi. So there are invaders and scens weapons left. Possibly invaders rifle would be easier to get

Bastion Stairs Blood Lord Rifle is a very good Rifle with Flat +5% more Damage.