Sorry about that. Sometimes, a thread squeaks by un-noticed.
Did you get your problem sorted out? If so, great.
If not, you can help the clutch by scuff sanding the contact surfaces of the clutch shoes lightly. Roughen them up just a bit. Also, make certain that the inside of the clutch bell is clean of any oil or grease.
Tightening down the spur gear in the fashion you mentioned will help the engine engage the drive train a little more quickly, but it will also remove the spur gear as a shock absorber for the drive train. Be careful when locking down the spur gear.
Other than that, the rest is in your driving technique. If you drop the hammer immediately on the engine, then you might spin it up quicker than the tranny can handle.
Have fun, and as you stated...let her rip.