One trick I have discovered is that if you create a field on a layout that uses the Classic theme there is no field padding. If you then copy the field itself onto your themed layout the classic field formatting will be retained and, presto, no padding. This has the same effect as removing styles. Either way you would THEN need to apply your own formatting as required. I guess if you had done things in this order in the first place … … We live and learn!
I have no clues on the second matter.