Rust crashes

So, I’ve been having trouble with Rust recently since the webplayer has gone and I’ve found that when I join a server 1/20 times the game would crash with the error ‘rust.exe has crashed’. My PC is currently crap and I’m in the process of making one, however when I launched the game with the -force-feature-level-9-2 or 1 or 3, I was able to get from 25fps to 58fps but still had the problem of the game crashing.
My specs are-
HD5450 1GB
4GB DDR2
Windows Professional 32bit (OEM)
Intel Pentium 4 2.8Ghz
(The computer is a Dell Optiplex GX620 HT)

If you are using force feature then play in windowed mode.