Gaming PC 3 years before college?!

So I am thinking about building a nice ass gaming PC at the end of this year (I will be a sophomore in high school) worth about $4000. I DO NOT want people telling me not to spend so much, no advice on my lifestyle whatsoever unless you really feel the need hahaha. Is it a bad decision to build a gaming PC just 3 years before I leave for college?
Questions
1: Will I be able to bring PC to college assuming roommate is ok with gaming?
2: Is it a bad decision to build a gaming PC just 3 years before I leave for college? ( I will still get use out of it when I visit home provided I do not take it to school)
3: Do you (or did you) know anyone with one in college? If so how did it turn out?
4: If I should take one how is the internet? Good enough for high-quality gaming?
5: Is water cooling an issue for short bursts of transportation i.e. home and back to school for summer?

Thanks for the help!