90 lb. f/flashing?!
no....Shazzapple gets it, though.
In Miami there are thousands of flat additions called "Florida Rooms". A BUR (eg. two PLY 4 w/Ruberoid Granule cap) hot-mopped over tapered insulation holds up well and greatly improves drainage and energy efficiency.
Low slope/steep slope transitions are Roofing 101 for a pro. Find one.
Do your homework. Pick a system. Get 3 quotes for that system. That's as DIY as you should get.
Yes, matter of fact I do know a "trick" for removing those
pesky lil' tile at the tie-in...