[This response should not be construed as a Halachic ruling on the question. Rather, it is an exploration of the topic to help our readers become more familiar with the issues involved.]

Technically, a person does not have to check out a spouse for Pgam Mishpacha, as long as there has not been any testimony indicating that the person is unfit to marry him (see Shulchan Aruch EH 2:3, and ha'Nisuin k'Hilchasam 2:2 with footnotes at length). However, one of the results of the beautiful Ba'al Teshuva movement today is that potential suitors whose parents are/were not known to be strictly observant might not be Halachically eligible to marry their betrothed for a plethora of reasons (I personally know of many such cases). I would therefore suggest in such a case that a knowledgeable person ascertain that the person they would want to marry is indeed eligible to marry them.

All the best,

Yaakov Montrose

[I hope this response has clarified the issue. For all practical questions on the issue, please consult your local Orthodox rabbi.]