[Rez]

1) Think I answered that one in another thread.

2) Battery Space

3) You have more weight, but a more important factor is, where is that weight? LiIons let you sling that weight low for a good center of gravity. You shouldn't be rolling.

4) If they're AAA sized I suppose they'll fit a AAA holder, but honestly I've never seen anyone do this. Most people solder wires to them and plug the wires.

I really wouldn't skimp on the charger. Save up the money and get yourself a decent lithium charger. You're already making an investment, protect it, and yourself. LiIon batteries can get pissed off if you charge them wrong. And by pissed off I mean on fire.