Update: ok so i think i found out what is causing the random, out of no where, vibrations. Reinstalled slimkat with complete clean wipe, still having issues. Then i decided to turn off anything that causes vibrations, starting with keyboard (which i had turned on for 1ms duration). Luckily, that solved the issue for me. I havent had random vibrations since then.
This is just a possible solution for others who may encounter same issue in the future.