I have 30mm tires but same bike and weight. I ran them as low as 40psi, it sure was cushy but they were slower. I also had a couple rim strikes which if I was running tubes would have likely produced pinch flats. Now I inflate to 60/70 and they are probably as low as 50/60 sometimes... for example if it is wet I won't re-inflate.
Agree with above poster that your biggest improvement now would be to get some more supple tires, those Gatorskins are rocks. Also you don't want to go a lot lower on the pressure if you want to avoid pinch flats.. 50/60psi or so at the lowest would be my guess. Its fun to try that out for a bit if nothing else for the learning experience.