Total agreement for number 1,2,3
regarding 4: here is the
Players HandbookAll the races and classes from this book will probably be there, maybe more (e.g. githyanki companion confirmed)
All classes have several subclasses. You start as your base class and you can select a sub class later, usually when getting lv. 3.
If I understand the rules correctly:
- Every caster uses spells like a sorcerer in the old games, plus you can cast low level spells at a higher level for greater effect.
- The difference between wizard and sorcerer is, that wizards gain bonusses dependent of their spell shool of choice (no more forbidden opposing shools)
while sorcerers can spend points to cast their spells with meta magic effects and some bonusses based on their bloodline.
Prof. Dr. Dr. Mad S. Tist 
