Painting over skimmed walls and ceilings

You should just mist coated then it would show any areas for prep work then apply two further coats of emulsion and it should complete work But it also so depends on how good the over skim of plaster is if it's not done well it will never look good with out a lot of prep work .hope this helps.

I apply a little pressure to the roller this then gives me an even smooth finish and do not apply the roll to much because that can affect the finish.

Unfortunalty, unless the plasterer has done a perfect finish, at this stage you will need to put the mist coat on, and then sand down any imperfections to gain this perfect finish, then mist coat again if alot of sanding was needed. Once you then put your, 2 top coats on, you will then have nice perfectly smooth walls. It really is all down to the prep.

New plaster should require minimum prep at this stage. A few dings etc to fill. A little rubbing down in the corners and sanding off a few trowel lines is acceptable. But these are minor things. Sounds like you have an entirely unacceptable finish to deal with. You cant also just keep sanding away at the plaster either On the occasions ive had to deal with this iive applied a thin coat of easifill then abraded. Or if its that bad also hung linimg paper

It depends on how good a job the plasterer made of the walls to start with,I always give new plaster a light sand then a dust down ,never usually apply a mist coat unless specified by the customer, normally two coats of good quality paint will be good enough,saving paint costs and time ,but sometimes a bit of filling is required after first coat is applied and then touch up the filler when dry and sanded then apply final coat ,Gary the painter