If any of these symptoms are in evidence then there is the risk of rising damp being present. However a process of elimination is required as other cause of dampness in buildings need to be eliminated as they require other remedial treatments.
This is where there is soil, dirt, or a garden bed, etc. which is higher than the inside of the wall where dampness is evident and is entering the masonry laterally. A cellar situation or walls built into the side of a hill are obvious cases where lateral damp would be the cause.
N.B. Always consider the above as possibilities if the house is less than 40 years old.
Having identified the cause of moisture is rising damp then it needs to be treated by introducing a new damp proof course. Sanding back damaged walls and/or plaster and repainting, covering the wall with plasterboard and any other band aid remedy will prove to be both a waste of time and money as the problem would not have been resolved. There is some urgency introducing a new damp proof course at this stage as rising damp in masonry is like cancer in humans, the longer you leave it untreated the more serious the condition especially if salts are present as evidenced by white powder on the surface. The reason the salts cause so much damage is that they are continually moving. On dry days with low moisture in the air they contract then on wet days or days of high humidity they expand so they are continually expanding, contracting, expanding, contracting until the masonry starts to crumble and mortar turns to dust.
How long does this take? Who knows as there are many variables, it could be years or tens of years but it will happen unless treated.