I noticed while parked today in my garage with engine off that I can shift my gears without depressing on the clutch, is this normal?

It shifts fine while driving...

(I installed a nismo shift **** not too long ago and took care not to torque the shifter itself on installation, don't know if this has anything to do with it.)

What do you guys think?

 

perfectly normal. With the engine not turning, the synchros do not have any work to do to, so the gears are meshing easily by themselves by not being in motion.