>>> First queston is, can you subclass it or is it a sealed class?
>
>I have subclasssed it in code and can use that subclass on a form. I'm new to .net so don't know else to subclass it.

You pretty much have to do it that way.
One thing you can do is set up the base grid the way you want it on a scratch form then open the x.Designer.cs file and copy the relevant bits of the Form designer generated code into the InitLayout() of the subclass. You'll need to delete the 'this.grid1 (or whatever) from each property but it's probably better than trying to do it all manually.