Right after the whole Bodhi episode I got thrown into Chapter 4 (I just hit chapter 3). Should I have held back and finished up all the "mini" quests before sailing?

The quests are usually still there for when you return. There are very few timed quests in the game: you would probably know already if you have or have not started/completed them :)

Many people like to leave some of the quests until after rescuing Imoen -- she can then also gain the benefit from the added experience point earned.

You will know if you went too soon if you keep on reloading in Spellhold and beyond. Try to have at least some good weapons (+3).

do what gives you lot of money, and go to spelllhold

Personally I'm a rush to spellhold weenie. Get you're stronghold and get going, at least if you're a friend to Imoen. Besides, unless you've installed the always toughest random spawn in dungeons from the tactics mod or something like it you're unlikely to need great equipment any time soon.