Verbing

The article below talks about the conversion of nouns to verbs called "verbing." And I have two questions.

http://oupeltglobalblog.com/tag/nouns-used-as-verbs/

1) In the article there are sentences like these:
"it seems that nouns are being verbed wherever you turn."
"Passengers who are transiting need to follow the transit signs."

My first question is, is it OK to use this kind of verbed nouns as the adjective? (I think I just used it.) Let's say, "I am a transiting passenger." Do you feel fine with them?

2) I'll quote from the Office.
Holly: You know... in case if something changes.
Michael: I don't have an in case. Do you have an in case?
(here, they are talking about in case they break up.)

I hear this kind of a-usage a lot and have seen this type of grammar as some kind of conversion that is similar to the verbing. Is my understanding acceptable to you?

Thank you,
M