Lowering the compression won't be any significant help to save the engine, and it will certainly make you lose power unless you are at WOT. Two of the three C's still apply, cams and compression are your friend for making power. There is also a unique slanted squish area on the pistons that depends on the head being at the correct height from the top of the piston. A thicker headgasket will defeat this, and will make the engine more detonation prone, not less.
As strong as this engine is, there is very little a 50 shot could do to hurt it unless you get a backfire. A backfire could result in a cracked intake manifold (since it's plastic), and the design of the intake is NOT nitrous friendly. With the plenum on the bottom, it just invites fuel puddles to form and create ideal conditions for a backfire through the intake. I would be a LOT more concerned about this than a problem with the basic engine. Scionspeed is making a lot of power with the stock configuration (I think they are going to start finding the weak links pretty quickly now) and it is well over twice the factory rated output, as is typical for Toyota engine designs. I am a bit concerned about the gearbox and driveline at their ~500 hp numbers though, Toyota is NOT well known for strong gearboxes.
As strong as this engine is, there is very little a 50 shot could do to hurt it unless you get a backfire. A backfire could result in a cracked intake manifold (since it's plastic), and the design of the intake is NOT nitrous friendly. With the plenum on the bottom, it just invites fuel puddles to form and create ideal conditions for a backfire through the intake. I would be a LOT more concerned about this than a problem with the basic engine. Scionspeed is making a lot of power with the stock configuration (I think they are going to start finding the weak links pretty quickly now) and it is well over twice the factory rated output, as is typical for Toyota engine designs. I am a bit concerned about the gearbox and driveline at their ~500 hp numbers though, Toyota is NOT well known for strong gearboxes.