Flora Danica contains Leuc. m. cremoris which produces CO2, and eyes - not a good choice for cheddar. I would use an MM100 which includes Lc. b. diacetylactis. This bacteria produces a buttery (diacetyl) flavor and sometimes a tiny bit of CO2.
I can't help you with goats milk procedures (and it will be a little different) but you are on the right track with your curds and floc time and a little extra cream never hurts. But the real key to a milder softer cheddar is acidity. With a cow's milk cheddar, you typically drain at pH 6.1, cheddar, then salt and hoop at pH 5.3-5.5. If you want a cheddar that isn't so dry just don't let it develop as much acidity before salting.
You might look at a recipe for a Double Gloucester. This is a style of cheddar that is not "cheddared" for as long and has a higher pH. It is a wonderful, smooth, mild cheddar even without extra cream. I have one cheddaring right now and will salt it at pH 5.7
I may have to try this one.