3.4 version has overlay feature which PokeCalcNTR currently uses.Hey that is really detailed response. I actually got it working last night. The problem was that i choose the version 3.2 NTR which doesn't work. When I used 3.4 it worked after.
If there's a mini FAQ that answers all the above issue it is really helpful for beginners! I also answered your questions in my quote. Thank you