Bottlenecked no
Overclockable No
6700 Will fit in that socket.
Future CPU upgrades No unless the 7700 is compatible but it is not worth the upgrade from a 6700 if you ger that
If you went AMD
Bottlenecked with a 1600 no
Overclockable yes with a b350 board or higher
Future CPU upgrades Yes, at least for another 1 or more CPU generations.