My players have been using the -5/+10 feats in a real game. They are OP at the very least, I would go as far as saying they are broken. When you look at things like the extra attack for valor bards or the bonus dice of damage for clerics, the +2 to a stat bump for the price of a feat and the fighting styles having feats that grant +10 damage on all attacks are OP assuming the PCs can negate that -5 penalty to hit which is what bless does. They can also gain advantage and there are a lot of abilities/spells that do that.
The grapple feat is not very clear probably needs a rewrite, Warcaster, Sharpshooter, Great Weapon Master are either feat taxes, overpowered or idiot taxes much like natural spell, power attack/cleave and point blank shot/rapid shot were in 3.5.
Polearm Master, Crossbow Expert and maybe sentinel are not to far behind either.