It's still an engineering degree, they are going to look at all math, science, and engineering courses you took to evaluate your eligibility. You should google the cost of attendance for your schools, but just to compare it was around 82k for a masters in EE at Uminnesota and 120k at UMichigan. That's if you take loans for everything room, board, tuition, etc..
I think it its very unlikely you could count AP credit toward a masters.
Ga tech was on your list and a good number of your question are sorta answered on their faq page, other schools should have them as well. http://www.isye.gatech.edu/academics/graduate/faq/
They are always going tho encourage you to apply, but they do have on there that if your background isn't math science or engineering you have to prove yourself more to them, as someone else mentioned linear algebra looks recommended. They also address low gpa from top school on there too.
Just being realistic, not trying to discourage you/anyone from applying. Just know you will need to show the admissions committee even more why you deserve a spot, and you did very well on the gre. You might look into the gre subject test they mention too.