are there any major game glitches for new runners to know about? how much of the game can be skipped?

There where no known glitches in this game. Anyway, the player FoxNation was the first public known person who found a glitch just in January 2020. It skips a cutscene of some seconds. You can find the glitch documented on his youtube channel. Until now it is the only known glitch as far as i know.