every time this game has an update it's a nightmare to install it, first u download, then apply, then move (?!), then configure it and each of those steps (but not the download) takes forever!!! there's anyway to make the updates faster?! i think i passed more time downloading and updating the game than actually playin'it!

With 40 Gb game only SSD can probably helps. Not sure what you have to move though.

AFAIR, it's a simple shell script with packed data. It's single-core by design.

It is indeed a shell script which contains self-extracting gzip archive. Which is, in its turn, a binary ELF file which contains both decompressing code and compressed data. So we have following options to utilise several cores
1) that decompresser could, at least in theory, be multithreaded. There are multithreading gzip implementation, though that could provide some challenges regarding static linking.
2) the shell script can can run several decompresser subprocesses at the same time, which would not be that hard.