That sounds OP as fuck. I haven't been trying to steal at all. I've been really unlucky with non-unique gear drop so my party feels a bit on the weaker side now as a whole so that money would do wonders for me. But at the same time, I hate when gold loses it's value because you have nothing to sink it on.
I don't know I have 55k at lvl 11 and I haven't stolen anything in Driftwood other than keys and what not. I did steal a bunch in the first act though but since then I haven't bothered, lucky charm at 7 on my tank and he opens everything, I've started drinking alchohol before opening a bunch of containers at once(like when there's a bunch of crates/barrels/skeletons together), I'm getting purples and pinks everywhere to equip/sell and I have a barter char and raise attitude to 100 with every good vendor so I get stupid prices on buying and lots of money selling.
Mind you, I do have Thievery, my rogue has 7 or 8, can steal I think 12k per vendor, just haven't bothered with it yet since I figure I might as well wait until later if I find better thievery gear.
Lucky Charm and Thievery basically break money making once they're high enough. That's not counting the borderline exploit stuff like hiring pickpockets and what not, just using them normally. Bartering is so so, it's great combined with either since it increases your generated gold by a % but compared to them it's not that much.
Should I take Flight or phoenix dive?
If you mean polymorph wings, they act a bit differently so depends. Wings cost 1AP to activate and last 3turns, but you need another AP to use the ability to jump around, so 2AP to jump in a single turn. However you can keep using them every turn until the spells wears off. Meanwhile Phoenix Dive only costs 1AP and does aoe damage when you land, but it has a cooldown so you can only use it once. I replaced wings by phoenix dive on my warrior, I don't use it that often, I have The Pawn for small repositionning and for stuff too far I use other characters to either move the targets or kill them(rogue).