Quotes are gregdabuckeye's
"I bet tolerance is a modifier to reproduction on hostile (domed) worlds."
I don't think so. I think it improves reproduction on planets with a bad "condition". All planets have Conditions (Optimal, Plauge, etc), that can be improved by researching Planetary Utilisation. I don't build those facillities (that improves the condition) because it's not worth it (plauge is not actually a condition of a planet and can only be cured with medical bays - and now I lost the topic).
"The natural merchant ability seem quite strong to me (free spaceport) when facility spaces seem to often be at a premium."
When I started to play I thought ALL planets had to have a spaceports and I always picked the natural merchant trait. But then I realized that only ONE was needed in each SYSTEM. So now when I look at it i think: if only looks could kill!
"Am I stupid, or does picking a neutral race with no mods seem to be a bad choice when you can get a +5% research advantage with no disads?"
You're not stupid (well, you probably are in some way -
- since you are human - but not in this sense).
It's the same thing with other things in the game - it's unbalanced. Especially the cultural traits which CAN'T be modified either (not when I tried anyways). But I think they are fixing all that - or making it able for yourself to fix it. BUT - Since there's a new patch out faster than I can finish a game I'm NOT complaing... yet. "Why"? I dunno why.