Hi. Mike Miller here again. I got frozen out of Mudcat contact for a couple of days so I am late in responding to the kind folks who have answered. Let me try to cover a few points.
Nursing homes, retirement communities and other senior gigs have, in common, a much older audience than folk clubs. Another difference between the two audiences is their musical tastes and tolerances. The folk clubs are more lax in areas like prompness, appearence and professionalism. This does not mean that you will need a tuxedo for the "altes", but showing an audience respect by dressing in something other than workclothes is never a bad idea. Senior jobs are booked by Activity Directors (sometimes called Recreaters). They value reliability, neatness and audience involvement.
Senior facilities, in the US, are usually, privately owned and operated. There are municipal and state run nursing homes but they are in the minority.
I am not, quite, sure how to respond to the questions about repitore "integrity". I am an entertainer. It is my job (and I love my job) to entertain my audience. It is not their job to provide a forum for my integrity. It does not bother me to sing Chistmas carols or old gospel songs, even though I am not a Christian. I sing "You Are My Sunshine", a song written by a racist but beloved by all American audiences. My song list is determined by my audience.
They are my customers and I love them, I really do.
The big difference between being a professional and being an amateur is in one's attitude. Mine is not better than the hobbyist's, it is just different. But, if one choose to turn pro, it is wise to adopt a pro approach.
I have spent a lot of time talking about senior jobs (there is a lot to say and share) but that is only one area of the market. We haven't, yet, touched on commercial, industrial and civic jobs. They pay better than nursing homes and there are plenty of them.

                   Mike