wolfspeaker did a pretty good job explaining this already but I hopeful can provide some more clarification on a few? I use PAX pretty often haha
Q: Is it okay to use it on the face? Are there any areas to avoid, such as around the eyes?
You can actually use it on your face, but I would only recommend this if you are mixing your own paint and pros-aid (which is what pax is) because then you could add extra pros-aid to your paint and make it more flexible. This keeps it from wrinkling on your face really bad. You can put it on your eyes too, but its not really nice seeing as you have to wait for it to dry before opening and being careful to not get it stuck on eyelashes (Using a small paintbrush or something eliminates most of that though) You certainly can if you are just buying the PAX premade but be prepared for a scaly texture.
Q: What is the best process of removing it? I know the remover is typically needed but is there anything else that might make it easier?
Ok well, even before removing it I totally recommend using some kind of primer on your skin (I use an anti-chafing powder gel) to protect it while also making it easier to come off during wash time. I just find the weak spots like around the hands and high motion areas like joints and rub it lose and off. Thats just me though.
Q: Being a guy, is it okay to apply something like this to areas like the arms that have body hair on them? I'd really rather not shave because it would look/feel odd.
You can, it will hurt when you take it off a lot more however and if you paint the PAX on in a way opposite of your hair you will see it. It can actually make the PAX flake off easier too because the hair is laying funny and if you scratch near it the hair is looser and is more likely to come off. It can be done though so dont worry. For you, having some sort of primer and watching the way it went on in the parts with hair is essential.
Uhm I hope that was helpful to some degree,, if you even still need the information.
I hope you have a good experience with PAX :3