letting anyone use any first level ability from any class. One of the questions was about demi-humans and clerics: can an elf or a dwarf turn undead?
I could just skirt the question and point out that GMs have to define elves and dwarves in their campaign. Maybe they can turn undead, maybe not. Even though neither elves nor dwarves can progress as clerics, that doesn't mean they must be excluded from the base level of ability. Maybe that's the limit of what they can do?
However, consider this related question: can a Chaotic Fighter turn undead? The answer I would give is "no". First level anti-clerics can't turn undead, so why would other Chaotic characters be able to turn them? Given that not all human characters can use all the abilities of every class, banning elves and dwarves from using the turn undead ability isn't that huge a deal, and balances out some of the other abilities of those races.
After all, we wouldn't let a human Fighter have the abilities unique to a 1st level Elf, like improved hearing or the ability to sense secret doors without searching for them.