The trouble with offering a "handy man service" is that you really do need to have experience of doing this type of work.
Some jobs you might get asked to do may look straight forward on the surface but would you know how to sort out problems if things go wrong?
For example if you took on a small wallpapering job and when you removed the paper the plaster had blown and started coming away from the wall would you know how to resolve it?
With experience its likely you would of detected this problem at the beginning.
Or someone might ask you to do an "easy job" removing old tiles in the kitchen or bathroom and replace with new ones. But while removing the old tiles the plasterboard from the stud wall starts coming away in lumps and destroys the partition. Would you know how to restore it?
I get asked to do a lot of different jobs for customers but I turn them down even though I have the experience to do it because I prefer just sticking to doing windows. Its less hassle!
to be honest if you was a handy man, these are very easy things to fix imo, I would be totally confident to do this as have done up a couple of houses where this has happened, patching plaster is easy, as is fixing plaster board, if plaster board was damaged it would not destroy a partition any way as they has 2 sides, so you would only need to fix one.
I agree with people not knowing what they are doing should not do this kind of work, but anyone wanting to do it, and had some experience it would be good.
With paper on walls you cannot detect it before removing the paper (a lot of the time ) steamers can and do damage plaster thats not sound. but anyone that know this already would per warn a customer. I asked someone a few weeks back to quote to do my hallways as I dont have the time, and they said this very thing, if the wall paper comes off and the wall needs to be filled it will cost this much extra, we will not know this till the paper is of, more so that the paper could have been there years to cover the damaged plaster. this is a normal thing to happen.