"Free electives" and extra classes

[MNomadic]

I understand that free electives are just where all your leftover credits get distributed and don't make a huge difference in general. I'm curious if it makes a difference if say: you have 30 credits that could fit into your free elective category, though you only need 15. Should you choose to distribute certain classes over others to that category? What if you have many more classes done beyond the ~120 credits your degree requires. Do all your extra credits beyond 120 get onto your final graduation transcript?

The reasons I'm asking is two-fold: 

1) I already have enough free elective credits from previous programs that transferred in. I'm currently working on a few extra classes that I don't technically need but they are free and also interest me(teex, etc.) so I'm doing them anyway.

2) I still need to do about 16-20 credits at TESU for my specific program, so I may find it more economical to pay for comprehensive annual tuition rather than per credit rates. This would allow me to complete up to 36 credits through them. So I was thinking it may behoove me to work on some things that may go a little beyond my own degree requirements such as more advanced math courses.