2) Most reserve feats SUCK. Fiery Burst is the worst feat to get as a Sorcerer. He has so much greater damage potential with a great many other things at his disposal.
3) A Sorcerer who only has one or two spells worth casting in combat needs to go hang up his character sheet and roll a Fighter.
Seriously, by round 3, Murphy's Laws of Combat will have begun reshaping things, and you can situationally either use Save or Loose effects on stragglers, buff allies, or just look that damn cool by striking an awesome pose while the rest of combat is going on about you.
If you want blasting all day long, go Warlock. At least they do it better than reserve feats.