The proliferation of these extremely annoying time trials has made the game unplayable for me.

Wish I hadn't bought it now.

They're not required. You can do them or not. So, just don't do them? :)

They are required for such things as acquiring the tablets for the temples.

Yes that's true, 4 sets of 3 are at the 4 main temples. They do get far less annoying as you upgrade the skills though and you should blow past them on first attempt.

The other 100 time trials, or whatever number there are, are not required is what I meant and what I thought you were talking about :)

I'm having a great time with the game but I completely ignore these silly challenges. I don't bother for achievements or other meaningless rewards.