It's really difficult to just replace the creative force (Torme) on a sci-fi show and expect to move on perfectly. As for Peck, I also never cared what his personal issues were. If they were so overbearing, he should have QUIT. That's what Tracy did, when he felt he could not focus on the work. Honestly, I wonder if you're focusing too much on potential substance abuse. You're making him out to have been like Brian Wilson, unable to function. Partying on the studio's dime and nepotism, on a TV set, in the 1990's? You don't say??? LOL! If he were such a problem, he'd have been fired.
I still go back to the networks. Kari was only hired by FOX's demand, and we now know that consideration was given to eventually trim the cast down to Jerry and the hot chick. The buffoons there couldn't see beyond next week's Nielsen. Then you have Sci-Fi Channel, who made even less sense. Why pay for Sliders if you immediately treat it like trash? Could have had Tracy back, probably John and Sabrina to some extent, too. Nah, just leave Peck there, since we have to pay him anyway. Never made sense to me, but again, they took the fanbase for granted. It showed when their dumb Invisible Man show was a flop.
If you look at S4/5 Sliders, was it Peck's fault? Ehh, probably somewhat but I also think nitpicking on Easy Slider is also a bit misguided. Ironically, the hotel set came in very handy for those years, as it was a lot cheaper to film there when the budget was much smaller vs. FOX. Again, you still had some good scripts, and frankly, S4 had a lot of good ones. Perhaps the execution was not there, but many still stand out and are pertinent to today's world. My conclusion has always been that he simply was a BAD EP for Sliders, coupled with bad network decisions, and that's what we got. To blame it all on Peck's habits I find is a cop out, and to remain OT here, I stand by that he was just a unskilled yes-man who kept the execs happy by not rocking the boat.
As for your "Community" concept, ehhh, again, Peck and the Fox heads copied movies because they believed it meant ratings. They believed Kari in short shorts and cleavage meant ratings. This was NOT exclusive to Sliders, it has existed on most productions forever. It's a result of stupidity, laziness, and fear from lack of critical thought. Only in the last 10-15 years, in which truly unique programs like LOST or Stranger Things or Breaking Bad are allowed to run unimpeded by idiots wearing suit and ties, have television finally been liberated. Sliders was ahead of its time, and in today's climate, it could really be something.