Run-up with emergency brake set spins plane right

No need to be sorry! This is exactly the place for asking these questions!

ok...

What you've experienced is related to how X-Plane is simulating tire grip on surface. X-Plane is doing it...not *perfect* and lacking a bit. LR are improving these aspects bit by bit...

Anyways, this is what you should do:

Pull the brakes all the way just like you did. Then, advance the throttle very nice and slowly, gradually reach the needed RPM. If you will do it too fast, tires will "lose its grip" and will skid along...this is what happened to you. You've got this into a "turn" because of the overall moments (engine, torque etc...) that were working on the plane as a whole.

So...set the brakes, and advance the throttle nice and easy. It will hold in most cases (with the VSKYLABS LongEZ) with full power as well, depending on aircraft weight.