On your 3's and 5's there will be plenty of math but that is not to say that the math will be very advanced. Basic math (add, subtract, multiply, divide) will get you by but basic algebra is also very useful (ie: a=b*c ...if you're given "a" and "b" can you solve for "c"?).
The main thrusts of the Tfc 3's when I did it were famil with the pubs and load planning. Being trained as a Weapons Tech you know how to reference pubs and you presumably have an eye for detail; that will help you on loadplanning where a single miscalculation can (on paper) crash your plane - again with the plenty of simple math stuff.
I'm not in a position to speak to the possibility of being exempt from your initial 7 weeks but my gut says no. Worst case, you'll have 7 weeks of bird courses where you'll consume copious amounts of coffee and enjoy homework-free evenings and weekends. I can almost
guarantee that no one will be shooting at you and your accommodations will be better than a 10 man in the field
Where you're posted and what position you fill will determine what life is like for you after CFSAL but academically it won't be any more challenging than your 3's. Even your 5's is essentially a review of material covered on your 3's.
Hope this helps some. Feel free to PM me on any specific questions