If I want to defer my graduation because I'm not taking some of the mandatory program courses this year, how do I go on about doing this on Mosaic? Do I just not take the mandatory courses and it'll automatically not allow me to graduate this year?

Also, is there any disadvantage to pushing to a 5th year for the sake of taking other courses I want to take / boosting my gpa?

If I want to defer my graduation because I'm not taking some of the mandatory program courses this year, how do I go on about doing this on Mosaic? Do I just not take the mandatory courses and it'll automatically not allow me to graduate this year?

Just not take them.

Also, is there any disadvantage to pushing to a 5th year for the sake of taking other courses I want to take / boosting my gpa?

You lose 1 year of your life, and it will probably put you in bigger debt. Of course, if you spend that year working somewhere, and doing relevant projects then it's justified.

Doubt i'd take 1 more year just to bump my marks up, so many things could go wrong. Plus no one really cares about your marginally improved marks.

You can't graduate if you haven't taken the mandatory courses.

And Mac likes your money so it's not like you'll get an angry visit from the Graduation Police if you decide to stay an extra year.

As far as boosting your GPA, though, graduate schools are going to see through that.