I would suggest:
-no geo 13, not unless you can drain them better.
-use MA4001 instad of MM100, it will get your whey off faster and allow you to brine and dry. You should be designing the recipe to get your cheese as dry as possible from thelooks of the slip skin issue you are facing.
-more air!
-brine them, it will give you much better rind development and uniformity.
Your pH markers should be:
-rennet at 0.15 - 0.2 pH drop from start
-30 min set, not 60
-stir to a pH less than 6.3 (6.2 is best)
-Leave to drain in a warm area to pH 4.8 or less, this should take about 12 hours if you can keep the cheese at 70F. Immediately brine them in a cool (55F) brine and place in your ripeneing room.
Good luck.