Glad to hear you went down and tried 34 psi on the front. I suggest you experiment further and go down to 32 or even 30 just to see how the bike reacts and to learn feedback from the bike,(even though 33-34 psi is more conducive to your payload weight and it's where I'd be running the tire if I were you). Pressures of 30-32 are not going to hurt the tire, although as pressure drops, temperatures WILL rise. It will start handling poorly long before temps become a problem. As pressure drops the bike will steer slower and the tire will begin to roll and squirm to an unacceptable level in the turns and under hard braking. You don't need to be going fast to do your testing. I use a big dry asphalt parking lot and perform quick hard swerving maneuvers at 20-40 mph. Just make sure there's no asphalt rock debris to slip on in the parking lot.
As pressure is reduced, at some point you'll know you don't like it. That's when you start going back up until you get the best combination of handling and braking foot print from the tire. That lowest point for me with the Avons was 30 psi. I've settled on 33 psi. Lowering the tire pressures WILL make the bike handle a little slower but the many benefits definitely offset that minor negative. Once you get the forks sprung stiffer, you will regain most of the steering quickness and it will handle quicker than with the OEM springs. At speed, the bike will feel 50-100 lighter than it actually is. The same goes for the rear end if you change the shocks, but to a lesser degree than when you stiffen the front.
Raising the rear end 1/2" make a huge difference. The bike really responds faster to a steering input as the rear end is progressivly raised. This REALLY makes the bike feel lighter and I love the way mine handles with the added 1/2".