3 out of my 10 AP classes will be taken my senior year, how much does the admission process look for rigorous classes during the senior year?
Rigor in your classes should generally increase as you go to higher levels in school.
First semester or second semester? 
Seriously, though, remember that you are doing this for your own learning, not for outside validation or judgment.
It better matter I took 7aps!
just kidding! I actually took five of those because I genuinely enjoy those subjects and then two because you know college. And I think they definitely do matter, especially if you do well on them as indicated by your mid year report
I work in admissions: Senior year rigor matters. Very much. Lots of kids think that the junior year is most important, but senior year is equally important. Be mindful of this. Don’t slack off in your senior year course selection.
Sorry to butt in, but @annwank or any other admissions person, do colleges care much for things like extenuating circumstances that preclude the completion of required classes before senior year or inability to take more ‘rigorous’ classes due to timing not working out, although the school offers? Also, does class choice diversity factor in at all? And do things like self-study APs affect what colleges think of rigor?
Again sorry to butt in, but I know people who are worried about all of these things. For example, someone dropped a program with a strict schedule over four years after sophomore year, and got screwed over when none of her classes counted as elective graduation requirements, and so on.
Your GC can explain these extenuating circumstances in scheduling in his or her recommendation
Extenuating circumstances can be addressed in the counselor’s letter. Otherwise, adcoms like to see a student taking a rigorous schedule as determined what types of advanced, AP, honors courses are available in the context of your high school. If your HS does not offer AP classes, then yes, self study shows initiative for sure.
Don’t understand your “timing” question.