Hi Lisa,
I don't find your question (or your finding ambiguity in the words in question) to be as absurd or non-sensical as some apparently do.
To get you a step closer to the primary materials you seek, "Papa ..." was first released (by The Temptations) on their 1972 LP "All Directions". That may help you to find the lyrics, if any, which were published in that release.
A sampling of lyrics found on the 'net for this song reveals:
Wikipedia quotes that particular line from Papa as "alone".
Wikipedia has a LOT of the history surrounding that song, and seems to be in touch with folks who were close to its history - so it seems to carry some authority.
A variety of other sites seem pretty unanimous in quoting that particular word as "alone".
An interesting note is the sing365 site which, when the song lyrics are looked up under Queen as the artist - they say - as recorded by the Temptations, and quote the words of interest as "alone" - and give a copyright notice - making it seem that the source of these words had access to a printed version with a copyright notice.
On the same site, if the song is found under The Temptations, the phrase of interest is given as "a loan". This set of words credits the songwriters, but does not include a copyright notice.
The consensus of lyrics for "Papa" give "alone" - including those with pretty detailed history (Wikikpedia) or a copyright notice (the song lyrics for the song as performed by Queen, but listed as "as recorded by the Temptations).
But, at least one contributor to this site (plus its lyrics moderator) seemed to think that "a loan" fit the context of a no good man leaving his family with HIS trouble to deal with in the form of "a loan" to service - even when he was gone he was still causing them trouble. "a loan" makes sense to me in that it amplifies how no-good this man was to his family.
But, now you've got the name of the LP on which the song was first released by the Temptations - and for which you MAY find the lyrics published with it. It sure would be nice to find a reference for the lyrics as contained in the songwriters' edition - they are NORMAN WHITFIELD and BARRETT STRONG, BTW.
I hope you are able to get some primary materials to scratch this itch or yours definitively, instead of just a consensus plus a contradictory collections of opinions.
I, who do not have a big itch to scratch here, am swayed in the direction of "alone" because of the signs of authority (detailed history and a copyright notice) associated with the sources listing that homonym. But, as a thought experiment, wouldn't it be funny if you actually got hold of Norman Whitfield's AND Barrett Strong's (two) personal scores of that song, and one said "alone" and the other said "a loan"?
This is the stuff of which music history careers are made - getting at the primary sources that definitively resolve these ambiguities. If you get at some primary sources that definitively document what the correct wording is (rather than just compiling a consensus of folks' seat-of-the-pants takes), please get back to us with the bibliographic reference. It'd be a hoot to find out.
Best wishes to you,
Steve