No probs with the "Like" button I was only jokin',, If you tap the render on the walls does it sound hollow? I did a job like yours a few years ago and the render and plaster came off in sheets. That was old sand and lime render and skimmed over, it came off because when the plasterers did it years ago they must of just soaked the walls with water first (which was the right thing to do) before laying the muck on the walls. But I don't think the walls were drenched enough to kill the suction and over the years it just pulled away from the brick work. I don't know if yours is that bad but I think that it may of dried out too quickly and that is why you have got these problems. If you look at the horizontal cracks they tend to follow the coarse's between the bricks, and it looks like the mortar between the bricks has shrunk back and is causing the cracks. The wall looks quite dry so if the render comes off easy (Try putting a scrapper under it) and see if it comes off, If that is the case then take the whole lot off (Or let who ever is going to do the job take it off), Then you have the options of either sand cement lime , Bonding or dot and dab then skim. Have a look in my Albums for "Dabbing Walls" and that will show you how I sorted out the problem with the walls. If you have a plasterer in mind (make sure he comes from a person who has recommended him or ask to see his work) then he should know what to do to help you out. As for the little cracks on the ceiling then it might be better to get it papered and painted,,, If you fill them then it might open up and close again depending on the humidity at that time. Let us know what you think and I hope this has helped you a bit...PS,its the "Thanks" button.