secondary racking question / brew belt okay?

So I plan to do a secondary fermenter for my IPA. It says to move it in 5-7 days but before fermentation is complete. Am I safe to just rack to secondary in 5-7 days...I don't know how I'd know when fermentation is almost done other than the length of time passed. oh and it doesn't seem like you can leave the beer to long in the last fermenter... so if i go over 4 days, that's okay.

I guess i just know FG after 2 weeks and i get the same reading and it's around .09 i think it is?

I also plan to use a brew belt on the primary is that okay? the room is around mid 50's. i think the brew belt keeps the liquid 70-75 but i was told if it's above 72 it's a problem??

Temperature has always been a pain for me too. Slightly higher temperatures may ferment with "fruity" off flavors. If you use a brewbelt I would suggest checking temp a few times throughout the day, as it may raise higher than you want. If you take some notes you will be able to set a cheap electrical timer to keep it just right. I have had no choice but to ferment hot in the past and the beer was still fairly fine.

As for going to secondary, I wouldn't try to get too technical with this. If you want to take a gravity reading I'd transfer it when it was about .005 away from your expected FG, but wort will usually ferment a little bit more when you transfer to a secondary.

It's cleche, but true,
relax, don't worry, have a homebrew!