If the cone or filter is exposed then either enclose it or move it away from the engine bay heat. A well positioned cold air feed will be beneficial too.
The flywheel and diff mod won't add any power but will make for a more fun experience
A remap is very much a mixed bag, I found it to be worthwhile and have never regretted it. You'll see improved afr and around 8-10 bhp on top of the breathing mods and decat.