I like this plugin but you *might* consider that it is a royal 'P-I-T-A' to format labels for check boxes when the label comes before the check box (on the right-hand side). Since the variable length of the field is determined by the label and not the check box - it would not be necessary to format check box labels (for single lines) if the check box were to come before the label (on the left-hand side).
Having the check box appear under the label can be confusing to people. Especially if the number of check boxes is extensive.
Most of the label css rules are generic and as such if you change a css rule that works for one item it won't work for another - it forces you to add specific selectors for each label you DON'T want changed. Removing a field just makes the job of formatting worse. I understand that label selector ids are probably dynamically created and removing a field will make any rules specifically created for that field useless.
On Another Note
Deleting a form re-numbers the forms.If you delete a form between say 5 and 8 - the pages or posts that reference a form may or may not 'point' to the correct form after removing one because the form numbers are apparently renumbered. Deleting form 5 between 4 and 6 makes will make 6 -> 5 and the former 7 becomes 6 and so on. Why aren't the forms referenced by a name? or some other variable that maps transparently to a form number.
I believe, however, that your plugin effort is very good. Much better than most attempts at form creation and it certainly has options. But, I just had to explain to my wife that when she remove that form she removed that it changed the numbering of every form after it - she didn't get it.