look at the labels on the bed and at the feet of the corpse then look at the cupboard, down left on the screen it proposes two names, each one gives a code, note them then go in the second room click on drawers it asks for a code, do it twice each one with diffrent codes
smash the vase? Do it and "cut" the vent open. When you are inside it use the glasses and the rope.
get the painter away, go to the bathroom, throw the paper in the toilet, flush it and then go the painter he should go to the bathroom
Check the staircase, especially the railing, outside the room. There's something you can take. Use it with the plant then leave the house.