my cars neutral light blinks while in drive, and doesnt shift right,

From your description , it sounds like A/T problem , not engine problem. Have a shop scan the trans control module for codes , that may save time and money in the long run. CANNOT scan or read live A/T data with any generic OBDII 'code-reader' that I know of.

my AC leaked inside my car also. Freezing cold water all over my feet and passenger's feet. The mechanic cleaned out the area under car where the drainage hole is located. Seemed to fix the problem. Try to locate drain hole and see if it's clogged. Although, I still get an awful smell of antifreeze in the car oftentimes when the AC is running, especially when running on max & recirculate. Especially happens when going up hills or making lots of sharp turns.