I'm well aware of sharpshooter cheese, it's one of the other things that bug me but I just put it under dex being too good.Sharpshooter + Crossbow Expert = 3 attacks per round at Tier 2, ~18 damage each and you can stay away from thick of combat. GWM is good, but it's worse than hand crossbow
If I was going sword-n-board, I'd say Str-builds are better. Yeah, Dex is a useful stat, but being able to shove and grapple effectively is better than +2 iniative.
As far as shoving and grappling, if you allow a shove with shield master before the attack it does help. However, the "official" rule is that the shove has to happen after all attacks and I think the feat is practically pointless. As far as grappling, I don't think I've seen it used by a PC in 5E.