man up and get out teh sledge.
re-sheet rock it. Depending on the age of the house the ext. walls are prolly blown in insulation. which settles over time, leaving voids up on top. Heat rises. Heat passes through said voids, wasted money via heat bill.
Not only will paint over paint, over glue, over paint… look crappy, there are more gains by taking it all down, putting in new R11-RXX depends on the outside wall framing, vapor barrier, new rock, taped and sanded. then painted. retrim it and it will look MINT, and %200 better than just painting it and calling it a day.
If you dont have the money to do it now, save it, dont waste it on paint and glue remover and time. Get a home loan, talk to the bank about maybe a rehab/remodel loan, whatever you can do.
Houses = investment (as you know). Its like building a car. Dont put ebay parts in it and expect it to last, run/look right and get your money back out of it. Do it right the first time.