hey! Welcome!
I believe is true for all PT school that you can apply while taking pre reqs. Usually you apply in fall or beginning of spring for the following fall so it is common to still have prereqs to be taken. For the GRE I would think only you know the time you need because we are all different. However, you should really plan to take it well in advance. First, results are avilabe after 15 days, Also, a lot of people take it twice in order to obtain better scores and you can only take it once a month, and is by appointment so availability is limited in some areas, so yeah you should really plan ahead. Also, if you got/get financial aid you can obtain a letter so you can get a discount when registerin for the GRE. It takes like a month too, I found out late so I couldn't take advantage of it =(
I don't know if you work as an ide now or plan to, that's good exposure, and I learned a lot just volunteering. I also think that for interview purposes, it helps to have a extra curricular activity. I do ballet and I was able to incorporate that in my interview. It helps me relax AND gives you knowledge about muscles and movement, and also check out the APTA website once in a while so you can check out what's going on in PT