Yeah, if you will take Chrono path, it is better go all the way, since you are planning on going PvP then yeah, FB is not a good choice since you need to be close, unless you have a good CC group with you, but even so.
FG indeed can’t hit flying targets, but if you are in a group with a linker its another story.
In the end, it is a matter on what will be paired with what, in all honesty, i would go Linker Chono setup for a chronomancer build, but then again, it would be heavily dependent on parties.
But FG for PvP is a good skill, specially against cloaked enemies. and depending on where you set it up, it can cause a huge mess on the enemy lines lol.
Just take not that, if you don’t level your enhance attributes, you will lack damage later on, so whenever you have extra cash hanging use it to level these attributes, on my pyro sorc i did up to Lv 40 and at Lv 248 it still lacks damage, well my gear is not really that good for DPS tho.