Even if crazy Paul antics could cause issues at the convention, no other candidate is going to try to depend on it; if Romney has the pledges (by whatever definition) of 1144 delegates in June, Santorum will drop out and endorse him. Even if the Paulistas try to pull something, they'd still be a minority at the convention, and it would be a bit late for the Santorum folks to try to put together an effort at the convention several months after dropping out.
I think this rule might have a bearing on this:
Each candidate for nomination for
President of the United States and Vice President of the
United States shall demonstrate the support of a
plurality of the delegates from each of five (5) or more
states, severally, prior to the presentation of the name of
that candidate for nomination.Rule 40 (b)
http://www.gop.com/images/legal/2008_RULES_Adopted.pdfNeither Paul nor Gingrich has won a plurality in 5 states.