joeplot001, wth reference to your questions,
1: Do the Left Rear exit door (Right next to the engine) have the protruding exit slide problem?
I don't think so. There is extra space in front of seat 36A such that the exit slide does not detract from your legroom. Keep in mind there is an aft-facing flight attendant jump seat in front of seat 36B which provides for a little extra space in front of the seat. As redzeppelin mentioned above, you won't have stowage space in front of you so any carry-on luggage will have to go in an overhead compartment.
2. If no to question 1, would 36A be better than 26A? Or any other exit seat for that matter?
joe, it depends on your preference. Seat 26A is also a good seat; there is not a Seat 25A so you would also have good legroom at Seat 26A. I always enjoy looking out the window; I'm fairly sure the view out the window at Seat 36A is not blocked by the engine nacelle, but I'm not positive, and of course, there would be no obstruction whatsoever from Seat 26A. While the IAE 2500 engines on the MD
-90 are fairly quiet, I have no doubt the flight would be quieter from Seat 26A as opposed to Seat 36A. Finally, I personally am intriguied by watching the flaps, spoilers, and ailerons operate, so Seat 36A would be a better seat if you enjoy that.
Something else to think about, it has been a while since I've flown Delta, but I remember some aircraft--I think the A320/A319 and DC9s--have something called "low profile" seats installed at exit rows next to the windows and I always found these seats to be less comfortable than the regular seats. I don't know if Delta still has these on all aircraft on exit row seats that are next to the window.
Overall, I think it is a toss up concerning which is a "better" seat. If it were my ticket, I think I would select 36A, but that's just my personal preference. I don't think either are bad seats.
Is it possible to select 26A on the MSP
routing and 36A on the ATL
flight? That way you could have the best of both worlds and know which one you would prefer if you fly future MD
-90 flights. I think that's what I would do.