Minsc said:
The DM is supposed to have fun as well, and I won't have fun with their characters as is.
You might want to think about that statement a bit before you take over as DM for your group. You should be able to enjoy running the game but not if it comes at the expense of all of the other players not enjoying the game you're providing. If that's what it comes to, and that's what you're ultimately planning here, what's the point? Railroading is bad news. It makes players feel completely powerless and irrelevant. You can expect players to start coming to your game with the attitude of "It doesn't matter what we do because the DM will just force us into whatever situation he wants us to be in anyway".
There are much less destructive ways to deal with this situation.
1) Talk to you players. Let them know that you feel they are overequipped. Try to find some in game way to deal with it. Perhaps they make some hefty donations to their favourite religions, or as another poster suggested have the loot slow down a bit until things level out. Don't threaten them with imprisonment and loss of all their gear if they won't come to the table, though.
2) If the players don't want to give up any of their wealth or if you skipped #1 then you get to an option that is part of the real fun of DMing: plotting against your players. There are lots of ways for items to be lost or destroyed. That is part of the risk of adventuring. If you can keep it in game without making it completely obvious and the players have a chance to avoid it then it's part of the game. You slowly nudge things in the direction you would like them to go, the players have opportunities to avoid your nudging, you can keep nudging, and the game goes on. You might even come to enjoy the process and find that it's not so bad after all.
3) If the players won't budge and you don't feel you can whittle things back to spec as the game progresses then perhaps you shouldn't take over as the DM. If the group has been happily playing in this manner up until now and you want to abruptly force your own style of game on them it's just going to get bitter and messy.
If you want to go with capture and loot stripping you can do it, but it's really better if you can come up with a less intrusive way of resolving it. I'd suggest at least trying to DM the group for a while as is to see if it really is as bad as you're expecting. It might turn out okay. If it doesn't, try to work with the players rather than bludgeoning them with your idea of how the game should be.
Anyway, I hope this hasn't been too preachy but you sound like you're new to DMing so hopefully some of this advice will help. In any case, if you ever hear yourself saying something like "So, you're ambushed by a group of cloaked assailants. Don't bother rolling initiative, they overwhelm you easily. You wake up in a cold cell wearing only your underwear. All your gear is gone." then do yourself and your friends a favour and find someone else to sit behind the screen.
