Run OS X Server on Uni-MBP?

I don't know the main differences but I would bet it would come with a more lean install and without all the items needed for a macbook pro / mac mini etc. Maybe just the Mac Pro but certianly the xServe.

You should be able to install it, but if I'm wrong I know you can use vmware's fusion (don't know about parallels) to create up a virtual copy, which is what I would do.

 

No problems. OSX Server is just OSX Client + Server Tools.

 

Yes you can install it on the unibody mac, you can even install it as an upgrade on top of your os x leopard. The only thing you will notice different about it will be the server application folder and a new wallpaper.