3.a) Dex - Only affects certain maneuvers (thunder)
Fire - str
thunder - dex
wind - agi
ETC

If dex affected maneuvers at all you would notice a difference in AI behavior in and out of abyssea as you add + 90 dex. Being as that isn't the case, it is more likely a compensation for our low latent skill (what used to be C rank).

3b) Ahh animators. No other pet job has as little control over a pet as the one job required to full a useless item. SMN and BST can literally pick the abilities they want a pet to use. DRG (now) can also pick to heal/nuke regardless of sub. PUP however, cannot. We can 'influence' behavior by throwing a maneuver up and hoping the machine behaves, but thanks to one of the worst AI systems in a game, it in effect turns the one job who should have direct control of their pet (sense they use a device to control it) into the one job that basically has a honey-badger pet. It does what it wants.