prevent deletion of text units around form input element

Hi,

I think there's a need to prevent deletion of the 2 text units (previous and
next siblings) of a form input element. Otherwise, it appears that you can
end up in a state where you can't enter text before or after the input
element. For example, if you totally delete the text unit or if you insert
some elements in it like image. What is the suggested fix?

Also, is <p> absolutely required before the input element? If not, pseudo p
may be a better choice as the user does not see it in the code.

Thanks...
-An