John regarding rubbing on the reaction bars, you may find application of tyre shine type product/tyre gel/silicon on the inner sidewalls will stop the rubber tending to snag up on the bars on full lock.
I have tried lots of tyre pressures on my 4/4 - 26psi all round is my happy spot ( still running the factory contis) as i like a nimble feel. I don't think there is a right or wrong pressure but too little will stress the sidewalls and lead to spongy handing/feel. Too high of course could be dangerous - but a bit of common sense in how it feels on the road should suffice. I started at 30 psi and worked backwards to find my preferred setting.
