Or all four working against you at once. Quality latex products should have covered oil finishes (will never happen the other way around) but not if the surface was not sanded or otherwise deglossed. I have seen cheap latex where you can almost grab one corner of the room and peel it lose to the other.Could be paint incompatibility, moisture, no primer or bad prep work.
Older houses were painted with oil paints. If the walls weren't primed prior to transitioning to latex, you will have issues. If the paint peels off all the way back to the plaster, could be a lack of primer.
Anyhow, whenever transitioning from oil to latex or latex to oil an alkyd primer/underlay is a great equalizer so get in the habit of applying one. Alkyds come suspended in oil based solvents so are confused as oil primers. You work with the same tools like natural bristle brushes and you have to rinse your tools with mineral spirits. As mentioned, if the paint is peeling all the way back to the plaster, you will have to apply a priming sealer and start over.
And buy real paint store primers, underlays and paint. Stay away from the high markup box store crap.
Sounds like at one time you had steam heat in the house? The humidity changes from its use, plus the contraction and expansion of the plaster from heat during seasonal changes can stretch the limits of paint ---especially if placed over in inappropriate primer.
One other note I hope you have considered in your old house and not to make you paranoid. Given its vintage be aware you could have lead in the paint. Protect yourself and abate properly please. Cover central HVAC ducts when sanding and block off rooms you are working on, etc.
As for the pipe you want to get rid of? Without seeing it I do not want to render a firm opinion. If it is part of some legacy steam or hot water heating system that has been permanently disabled you can get rid of it I should think. If there is any chance it is part of a vent system or you are not sure its purpose, I would certainly consult a plumber before tearing it out.