As a person with autism, I don't really know why people who don't have autism are so interested in labeling characters as autistic. Especially as it is almost always villains or characters who get held up for mockery that get labeled as autistic. Rarely someone admirable or good.

And all the traits that you are associating with autism and Mr. Collins are negative.

Some of us on the autistic spectrum can pick up on social cues to varying degrees. Some people who are not on the autistic spectrum are also terrible at picking up social cues. Especially the arrogant male which is what Mr. Collins came off to me as. A pompous and arrogant male.

Some autistic people will practice compliments and other set phrases to try to be polite and better blend into society. Some other people will practice compliments and set phrases because they are ambitious and want to be seen as charming or to get ahead in society. Autistic people like myself are usually just trying to avoid getting mocked for everything we do.

Some autistic people would do well in a university setting. Some wouldn't. Same as people who are not autistic.

Autistic people can make friends and connections.

Autistic people may develop special interests. Those special interests are more likely to involve inanimate objects (trains are a common one, especially with males) or matters of academic/intellectual interest. It is rare for an autistic person to be obsessed with someone who is super rich just because they are super rich as we are rarely that shallow. Also it's kind of insulting to associate our special interests with something you describe as "absurd."