Answer:
The personal a is necessary
The first one is Hace Mucho Color
1. b. you use queria because if you say "quise" it means you stopped wanting to learn ballet sometime in the past.
2. b. you use conoci' because you've already met the professor in the past
You could say that you are less intelligent, as intelligent or more intelligent that Jaime. The thing is, you only have the options to write one thing because not all options would be correct:
Jaime es inteligente pero you soy más inteligente que él. - Jaime is intelligent but I'm more intelligent than him.
Hope it helped,
BioTeacher101
