People have different preferences and tolerances when it comes to driving, and often I tell people that they're being too aggressive but giving yourself an entire day plus (if you drive even 45 minutes from Carowinds to your hotel) to Detroit is a cake walk for a lot of people, including us. If anything, I'd take a 50 minute detour and go to Camden Park that day since you have time to kill, it breaks up the drive and when the hell else would you ever be in the area with the opportunity to actually go there? It's not a park worth going out of the way for, but you don't really have to.
That said... you know what drive I don't have the tolerance for? As others have said, the one from Great Adventure to Busch Gardens. I used to do this drive weekly and still do it all the time (unfortunately), so trust me on this... it's the worst.
If you leave Great Adventure at park close on a Wednesday night and drive to Baltimore, that in itself is a late night. Don't do that.
First of all, staying in a city if you're not actually visiting the city is a waste of money since the hotel probably won't have free parking, check-in will probably be a process in a large hotel (and you'll be exhausted with no patience for it) and the room rates will be expensive. Don't stay in a city. Stay between Baltimore and Washington if you go this route.
If you do this as you're planning to, you'll accomplish nothing by doing it because the worst part of the drive will be ahead of you in the morning (though DelDot seems to be taking that as a challenge and f*cking up the section of road between the Delaware Memorial Bridge and I-95 in an amazing fashion so I guess you'll have at least bypassed that).
Anyway, with this plan you'll wake up on a Thursday morning traveling with Washington DC rush hour traffic which is some of the worst in the country. Once you pass DC, you'll be on I-95 with the Express Lanes closed in your direction as they'll all be headed into the city that time of day which will leave you on a 3 lane road with no option to use the EZ Pass Express lanes in an apocalyptic traffic hell-hole longing for the sweet embrace of death.
You probably won't get to Busch Gardens until the afternoon and you'll be super pissed off when you get there.
I have 2 thoughts on how to fix this.
1) Flip Great Adventure and Dorney. This adds about 60 miles of driving and you backtrack a bit, but you can leave Dorney mid afternoon and drive to at least Fredericksburg without issue. Make sure you AT LEAST get to Fredericksburg.
2) Go to Great Adventure Sunday (and get a Flash Pass), go to Dorney on Monday (it'll be dead even though it's a holiday), go to Knoebels on Tuesday (which is a wristband day... with your plan it would not be and you would have dropped a ton of money), go to Hershey on Wednesday (which won't be nearly as crowded as it would have been on Monday) and go to Kings Dominion on Thursday.
Hershey closes at 8:00. If you want to drive a lot that night, drive to Fredericksburg via 81-70-270-495-95. You'll be there by 11:00 and then you can sleep in since you're only 40 minutes from the park. If you don't and you'd rather get up early and do a lot of driving in the morning, take 81 to Winchester, then take 50 to 17 to 95. It's a longer route if there's no traffic going the other way, but there will be if you don't plan to get to Fredericksburg Wednesday night. This route bypasses all of the DC traffic so you can just get a hotel whenever. Map them out a little though since a lot of that drive does take place in Bumblefucktucky.
PS: You can also switch Hershey and Knoebels. That means more driving, but more time to do it since Knoebels closes at 6 (and it's still a wristband day). You would also then be able to take advantage of the Hershey preview plan on Monday if you leave Dorney early which you might as well... because I mean... it's Dorney.
You won't have a problem with crowds at Kings Dominion or Busch Gardens on a Thursday or Friday. Don't backtrack like you had planned. There's no reason to do that. Don't buy a skip the line pass at either park. Go to Kings Dominion on Thursday and Busch Gardens on Friday.
At KD, ride Volcano, Backlot Stunt Coaster and Flight of Fear as soon as the park opens. After that, lines won't be an issue.
At BGW, ride InvadR early and save Loch Ness for later. Aside from that, lines won't be an issue unless you ride Le Scoot (in which case, ride it really early or really late).
You have a long drive to Carowinds, but it's fine if you don't get there until the afternoon or late morning so take your time. It's a Saturday, but lines probably won't be that bad. They rarely are at Carowinds except for the mouse and the flyer. Fury is a capacity monster.