I've been in eight galleries and I have to say that none of my gallery experiences have been very rewarding either financially or emotionally. I had a gallery on Cape Cod that sold about ten paintings/year for me but they went out of business. I would guess that these gallery sales have made up less than 5% of my sales. I think the gallery business is a really tough business to succeed in. The bulk of my sales have come from alternative venues.
In Oct '06, I quit my day job and went full-time as an artist. I opened my own gallery studio in a busy location in my small hometown. It's been very profitable because I have a low overhead, I paint and mix with the public all day, and I get 100% of my sales. I'm also my own business representative so I can often turn a "maybe" sale into a sale or a commission. And when business slows down in January, I do a few classes.
I sometimes wonder if the traditional gallery is an old fashioned approach to art sales. I recently had two big shows so all my inventory was out. I asked two friends to show their work in my gallery. They're both amazing artists. In six weeks they sold six paintings. These were their first sales since Christmas and one of them is in many good galleries. I got 40% of their sales which was good but not nearly enough to support my expenses in that period. Meanwhile, I sold eight paintings at one of the shows. (The other was a sleeper show at a college.)
On the other hand, I have a friend who owns several galleries and he sells only very very expensive work by established artists and dead artists. I know he's doing great but he only needs to sell one/month to achieve this.
So I guess my point is to try the gallery scene but look for other venues. I probably haven't answered any of your questions but since I wrote all this I'll post it.
Good luck!