Saeviomagy:
The Base AC thing was from this board a while ago, wasn't my idea. But it kinda fit with the concept, and it definitely helped balance.
A "touch attack" assumes that all I have to do is touch you for the effect to take place. But, it doesn't take into account thickness, for example. If you have an outer shell protecting you (even if it's just a really thick hide), the energy from the attack might not get to where it could really harm you. That's what the Base would represent: that part of the Natural Armor that can't be bypassed by anything.
Some people argued that this shouldn't just apply to Natural Armor; what about normal armor? For example, take Melf's Acid Arrow. Ranged touch attack that delivers acid onto the target. If I'm in full plate armor, why would getting splashed by acid harm the person inside the armor? It might eat away at the plating, and I'll want to clean it off, but shouldn't the armor help defend? Same for Flame Arrow.
One person suggested letting the target of a touch attack keep half of their Armor and Natural Armor ACs to represent this sort of thing.
As for the Good/Evil thing, it's really simple: if the spell uses Positive Energy, it should inherently good, if a spell uses Negative Energy it should be inherently evil. According to the PHB (the section on Turning) channeling positive energy is a good action, which is why only Good (or Neutral) Clerics can turn undead and vice versa. So, just extend that to these spells.
If Resurrection doesn't say anything in its text about what type of energy it uses, it should be usable by anyone. Not everything revolves around positive/negative energy.
(There are other ways to get around the "but Evil Clerics can't heal then!" argument, like letting Domains override this, but for this argument just say that it's the AMOUNT of energy that matters, that it only affects Heal/Harm.)