I already know how to import stuff into GM:S 1.4, but it doesn't actually make it compatible. For instance, many features built-in to older versions are still relied on. On the YoYo Games forums, it was mentioned that GM:S 2.0 doesn't even support backgrounds! And of course, the only versions of GM:S 2.0 you can get are timed Free Trial of the Beta, missing tons and tons of critical features (including the ability to import things, and whatnot) and the expensive, full version of the Beta. Not good for somebody with an unstable income...
If I'm able to back-port the compatibility scripts into 1.4, then maybe, but to my knowledge all they are actually built for are making GM:S 1.4 projects compatible with GM:S 2.0, not making GM 8.1 projects compatible with GM:S 1.4.