I'm definately not the final word on this. But my understanding after searching for the last three days on Samsung and the Indulge is that it can't be rooted right now. The standard tools don't work. There are a few Samsung Galaxy phones that have been out for a while that aren't rooted yet.
Tethering can't be done without rooting the phone. And Metropcs doesn't allow tethering. It's in your contract. I know this after researching it for my Archos 5. I don't think MetroPCS has any phones or plans that allow it.
As I'm sure you've seen, Silvist is trying as we speak, with no success. (Thanks Silvist!).
I can't wait for this phone to arrive at my local store!!