"I have much respect for Elena" works fine for me.

I hadn't noticed it. I'm still shaking my head at the announcers on the weather channel saying "temp-a-chur.'

If you're not talking about clothing, it seems to mean "customizable," which I hope is also a word and is more common.

"Stuff" is like "sugar." You don't have to say you have many sugar. You have much sugar. I believe it's called a collective noun. Other examples: material, money, water.