how to move the textmate file explorer to the right side?
If you're not using ProjectPlus by Ciarán Walsh, I highly recommend it. It makes some small but helpful improvements to TextMate's project features. It also allows you to specify the default side for the project drawer (which actually becomes a nice panel).
If you have it installed, go to Preferences > Project+ > Sidebar and select "Show sidebar on the right side of the window".