Is starting an animation playing in Start going to cause any problems?

I am currently starting to play an animation in Start, which plays fine, but i just wanted to make sure there isn’t other problems with this. I know if I’m doing that other Start functions might not have run yet, but does Start act any different then running something on the first pass of Update?

Nope. It’s will just be called after any Update, and after every Awake, unless you’re yielding something.