Did a 100 mile roady sportive yesterday -just to see how the other half live… and quite enjoyed it.
The Cheshire Cat I take it? How did you get on?
Re the hand problem, it's not uncommon and seems to affect the left hand more than the right, I'm guessing to do with the extra stretch required on the longer throw of the lever when shifting.
Try setting the levers a little higher or angling them inwards fractionally. It also helps if you can drop your elbows a bit, not only does it lower the whole uppper body but it takes a lot of the pressure off the hands as well. Too many people ride with locked out elbows and this forces the shoulder muscles to tense up as well. Try conciously relaxing your shoulders, dropping the elbows and just resting your hands on the hoods, you don't need a death grip on them.
Swap position regularly as well – drops, hoods, tops and also the curve of the bars just before the hoods.