So the confirmation speed may decrease if people do turn miners off and others do not tun miners on to make it more profitable?
No, the difficulty adjusts every 2016 blocks so that confirmations will always average about 10 minutes.
Sure, but since a retarget just happened, if 50% of miners shut down right now, blocks would slow down for the next 2008 blocks
Was there 50% less mining power 3 months ago? No, there wasn't.
25*350$ = 8750$ and 12.5*640$ = 8000$ so miners are making almost the same now that they made 3 month ago so I don't see why they would start shutting down now...
No, I didn't say they would, but the question was asked that if hashrate dropped, would it slow tx confirmations, and the answer is yes- until another retarget happens. An extreme case is if a lot of hashing power just stopped right now, it would absolutely be noticeable for the next 2000+/- blocks.