Let me ask you this. Let's say he wins a second term. What do you really think he's going to do?
When I read your post, I can only parse out about 4 specifics, but I assume there more than these.
You express concern about entitlements. Fair enough. His current budget purports to take a big bite out of entitlements. But won't he need Congress to accomplish that? I don't see the House going for it, and probably not even the Senate. Isn't the entitlements issue going to be a typical Trump move where claims he is going to do something (or even claims he did it), but it never actually happens?
Roe v. Wade. The only possible effect on Roe v. Wade that Trump could have comes through SC appointments, obviously. I've stated this before, and I continue to believe it. I don't believe Roe v. Wade will be overturned. Will the decision continue to be nibbled at here and there, as it has for the past 50 years? Sure, but whatever is going to happen regarding Roe v. Wade has already been cast in stone.
You worry about court packing. Well, honestly, whenever there has been a Senate of the same party as the POTUS, they take advantage of the situation to put as many "like minded" judges on the bench as possible. I believe that will always be the case. Is that ideal? No, not at all. But fortunately there is a bit of a lag effect too, since it takes awhile for litigation to work it's way up, and usually by the time that happens the POTUS is already gone.
That gets us to the worry du jour -- He just won't leave. I don't know what to tell you. I don't believe that will happen. I don't think the public would stand for it. If you think about it, electing a POTUS is a years long process. As we approach 2024 (assuming he's still around) there will be D's and R's running in the primaries, running ads, etc... You think he's going to run again? Even if he tried, you'd have litigation over whether his name could appear on the ballot in states that would challenge his right under the constitution, and I can't believe Courts would let him go forward, so then you'd have a Republican convention where someone else would get nominated and Trump doesn't even show up on the ballot in November. Even if he wanted to stay for another term, I don't see the mechanics of it.
None of those cause me to see the coming of Nazi Germany.