I have a Starcraft Pine Mountain which also has the 'full' door in the rear made by the fold up rear upper wall. I had similar problems with the door not wanting to open easily when the top was down. After a season of popping latches and pushing the top up 1/4" by hand to open the door I finally fixed it. I effectively moved the drip rail up to clear the door. To do this I removed the drip rail, drilled new holes that held it to the roof and then ran it through the bandsaw to take off about 3/8" of the top edge. I then re-sealed using fresh butyl tape and re-attached the drip rail. I have also altered the gaskets back there too so as to keep the rain out. So far it seems to be working.
As for the fabric thing, I just use my step stool to push it in by hand. I lower the top to about 3" from closed, make one round pushing in all the fabric, lower to 1", make a final walk around, and then close and latch. Not that bad.
I pull the canvas in as I lower the roof. Do it all from the inside. I support the roof with one hand and pull the canvas with the other. I take one run around the TC before latching and tucking anything remaining in. There is a little play to lift the roof and tuck. I have been able to do this from the ground in most cases. Only once did I need to use my stool which I use to enter the TC.
Only problem you may have is closing the door after the top is down. My TC does not have this problem.
I recognized the design flaw with the rear door too. I took out the rubber seal and I "redesigned" the metal drip edge with an angle grinder and then replaced the seal. Problem solved. I can't see how doing this could make it any less watertight. From what I see the back side of this camper is anything but watertight anyhow.
1992 Salem by Cobra 21F Fifth Wheel
Reese Classic 15K Hitch
2011 GMC Sierra 1500 crew cab shortbox
5.3 liter, Volant cold air intake & headers
I had the 1251's sister, a Real-Lite SS1608 I think it was. It had the short door so no conflict there but to be honest, I now have a hard-side because of the tuck-in issues...well that and I bought a big truck, too big for the 1608...ha ha!
Ram 3500 DRW CC, w/ Torklift tiedowns, SuperHitch, StableLoads, FastGuns, Airlift Bags and Wireless Compressor and Rancho 9000XLs. Real Lite HS-1810 TC. Starcraft 18' SuperFisherman Fishing Boat.