Basically what they would do is download the latest trunk, opened protocolgame.cpp and removed/changed back to use 7.6 specfic bytes. Changed items.cpp to load tibia.dat 7.6 format (not the same as the 8)
consts.h/const76.h has to be changed aswell
What are you talking about?
Just check it in RME. I think yes, but there will be much decreased IDs, and map won't be playable without much edits ;[