Are you guys sure that Feint slows movement speed at all? Heavy is the effect that cripples movement speed.
I was under the impression it didn't affect cast speed either, just auto-attack.
FFXIV - Slow (status effect)
If that's the case, then without the lancer trait to increase it's duration, it doesn't seem to be worth taking under ANY circumstance.

Personally, I think I'm going to be running with:
Featherfoot
Second Wind
Haymaker
Internal Release
Blood for Blood

Simply macro Haymaker to supercede Heavy Shot any time it's up, pop Featherfoot and spam Haymakers (if it's not an AoE situation). Makes a lot of off-tanking mechanics trivial.

Depending on the situation, I might swap out Second Wind for Invigorate... but it seems like any time I find myself needing TP, others do too and I'm already singing Paeon, which solves my TP issue...