This is my 1st playthrough of this game. (1st impressions is it's the worst game of ever bought)
I chose a Sorcerer & a pixie familiar to do the rogue work.
I waisted 10 hours on the game, but I think I'll start again tommorrow & just hire the Bard to open chests.
Hopefully it won't be the long tedious drawn out process that it is with a familar.
When the familar does open it, my cleric & summond badger are still there attacking the open empty chest.
Even after my familar & I are both killed by escaping prisoners, the cleric & badger are still attacking the empty chest.

How many mouse clicks does it take to get the bard to open a chest and take the contents?

the party AI is very crippled in the original game (as well as SoU, HoU had some improvements i think). personally i've never bothered with any henchmen and only had them onboard while talking through the dialogue in order to complete their missions and then ditched them.

dunno much about lock picking chests/doors since i always smashed them to pieces with two-handed weaponry and (improved) power attack (when playing as sorcerer i had three levels of paladin so had the necessary weapon skills/feats to do so).

there's a few things you can do:
1: posses your pixie first, (but it's also a few mouse clicks)
2: as your companions start to attack hit VEE (which orders them to stop attacking) VWE orders them to attack your target
3: add Tony K's AI, (improves enemy and NPC AI so fights are more challenging and henchies less stupid. It also allows you to configure some better default henchie actions, like not attacking chests.)

You can find Tony K's AI on the vault and there's a direct link in the add ons and tips thread on BSN. You can find links to both of those in the ultimate link list sticky at the top of the page.

Have fun :)

p.s. don't turn on item stacking or wandering monsters break doors when configuring the AI. They tend to break modules. )

Here's my helpful hint on chest opening. Chests seem to have a weak spot to sonic damage, even ones with high soak that you can't break open!

Find yourself a sonic weapon and smash away.