Skimming 4 walls ready for painting

To have everything level. Complete reboard to straighten walls and ceiling

1-2mm of plaster is enough depending on wall level. Skim beads generally follow what's already there and depending on what beads hes used sometimes they bleed through but the only metal that should be on show is the edging of the bead. Personally if your not happy call him back as you have paid for the job and the customer is always right. Hope this helps

If the job is solely ‘skimming’ unfortunately he has to follow the profile of the wall that’s there. He maybe should have advised you that it’s need bonding out or dab & boarded 1st to get it flat.

Generally 3 to 4mm of plaster after the second coat - if the plasterer is over skimming then he is partially limited to the conditions of the walls before hand. Some of this can be levelled out but sometimes it is simply not practical with plaster alone. If there is a large deviation in level above the window you may be better with other methods but once painted you are unlikely to see this. In terms of the beading it is perfectly normal to see the edging as this is where the plasterer will plaster up to. If any other metal is showing then an oil based primer can be used to stop any shadows coming through before you mist coat