Yes paint will adhere better to epoxy primer, than the regular cheap primer you get in a can.
Removing all the paint is actually the proper way to re-paint a car. I have been painting cars for over 20 years and trust me, you would not believe what people hide under paint and primer. Coat hangers, news paper to fill holes, excessive bondo, window screens from houses, screwdrivers to fill holes, and many more nightmares. With all the paint and primer removed, there is no mystery to what is under.
Yes this is the proper way to remove all the paint and primer. That way there is no mystery at all to what is under the paint and primer. I actually give you a huge pat on the back for doing this the proper way. 👍
Just make sure you keep an eye on every spot the paint stripper drips. For example: On your trunk, the body line around the trunk lid has a gap. If any of the stripper runs down in there it will remove paint around the trunk seals and might even eat the seals themselves. So watch those types of areas closely and you should be fine.