Re: open stance vs. closed stance
Yep, the usual tip is to move your back foot so your toes are pointing forward (well 45 deg or so to the stringer) rather than sideways. I find that my ankle mobility isnt great so while turning my feet makes the ride much more comfortable, it makes backside turns much harder, as my heel isnt on the board and I can't just lean into the heel. I gather one way to 'get around' this is to turn by throwing your front hand/shoulder upwards and push away with your feet, rather than lean your shoulder in and down, but I've never really managed it too well. Anyway, you arent facing totally forward (unless you are 'pig dogging'), but rather just opening up your stance so your hips are still at about 45 deg or so - its a matter of being able to see the wave without contorting.
You generally should have one hand on either side of the board, unless you are turning in which case it depends. You still lead with your left hand/shoulder (if a natural footer).