1. MulticlassingAD+D was too strict in some ways, not strict enough in others. I'd like to see a limit that o character can have more than two classes, period...with prestige classes rolled into the main classes as branches. Thus, a 7th-level Rogue who takes up Assassin becomes a Rogue (Assassin), and 2 levels later is referred to as a 9th-level Rogue (Assassin) rather than a 7-2. (myself, I'd prefer to make several currently-prestige classes base classes and do away with *all* the rest of the PrC's, but they seem to have become so ingrained now that this might be a pipe dream...)
2. Free MetamagicMetamagic in and of itself is a bad idea. Want a more powerful fireball? Research and design a different spell. Otherwise, let the spells do what they do. Oh, and to compensate somewhat, take the damage-dice limits off all spells.
3. SynergyI haven't encountered this yet, but the simple answer seems to be to decide before the campaign starts what materials are allowed (after you've had a good long look at them), and that's it. *No* material may be introduced mid-campaign.
4. Two-Handed WeaponsAgreed this is not working as it should. Perhaps get rid of the extra strength bonus, while increasing the base damage dice on some weapons.
5. Balancing Per Encounter Instead of Per DayAgreed; per encounter is an awful mechanism for three reasons: one, it makes casters etc. much more powerful than they should be; two, it makes a situation where an encounter repeats - e.g. the bad guy runs away and two hours later you meet again - something of an exercise in futility as you can't weaken a foe via repeated encounters; and three, there is and can be no clear definition of what constitutes an encounter.
6. Neverending BuffsBuffs of all kinds can be fixed by simply requiring expensive material components (a 100 g.p. gem, for example) for each casting. That way, the spells are there for times of need, but are less likely to be abused.
7. Combat Expertise and Power AttackThere's bigger headaches need fixing, but the flat bonus is a nice simplifiaction (say, half your BAB for Power Attack?).
8. Point BuyAgreed; point buy to me is an abomination.
9. RerollsAgreed; in-game re-rolls should *not* exist in any form unless by divine intervention or wish. (or Avoid Fate from the Deck of Many Things...) Re-rolling an awful set of stats as per the DMG I have no problem with.
10. Magic Item CreationMake it take a long time...months, even years...to create a single item. Make it rules-clear that the PC's job is not to make items, but to use them (and find them), and that a PC who wants to spend the time building an item is going to miss out on a lot of adventuring.
Lanefan