Where should I put the XP powertoys, like TweakUI and many others. In which folder?

I don't think that the PowerToys install with the standard Type I / Type II / MSI switches. Unless they are silent installers, you will have to install them through conventional methods.

you can install the powertoys through XPCreate. They'd go in the directory where MSI's go.

BUT, you'll have to extract the MSI's from teh downlaoded EXEs from microsoft. I think they all have them, except TweakUI. Someone made one, and you can find it at unattended.msfn.org and look at hte PowerToys section.