How to get 2 layers of paint off of concrete?

I do a lot of painting on the side, and I really feel you're spinning your wheels here and making extra work for yourself, and wasting money. There is NO NEED to strip this paint if all you want to do is........paint it again! As far as the cracks go, you can seal them now and just paint over it! Honestly, I've done this type of thing before, here's what I would do. If the paint is peeling or in really bad shape (and paint stripper chemicals are out of the question), I would rent a good powerwasher just to clean up the bad spots, and try to strip away the cracked areas. Then, I would use either a concrete repair patch kit, or just a good silicone concrete repair, and caulk up the cracks. Then, I would get "water tight" concrete/basement paint thats meant for concrete - just ask the paint guy. Then, put 2 layers of paint down, using a roller. Thats it, job done. In years to come, the cracks will probably open up again - there's really no way to stop it, just like our roads need repair and repaving every few years.

Besides the above, the only other option given your constraints is to sand-blast the paint off, but you're talking a real big project - and again really unecessary! The only way I would go through all this trouble is if I was restoring the concrete and not painting it again.

I'm a contractor and I don't see a problem with you filling the cracks, putting a coat of exterior primer down and then painting it the color you want. If the base color is difficult to remove than it seems like a good base. The only other suggestion I have is to use Hydrochloric acid. But you don't want to kill plants and it might damage weak concrete.

Sand blasting equipment can be rented or get a contractor