Your pace is going to affect what gearing you run. My gearing is very different between Mosport and SMP so I don't think you'll be able to have magic ratio that will cover all 3 tracks.
With that setup, it is one link different than what you have. So the axle will move forward by half a link.Sorry this is a very basic question .... does palying around with the sprockets effect the chain lenght? Likely gonna try Bakaboy's -1/+2 suggestion for shanny and I hoping it is as simple as swaping out the sprockets