Is it normal for switches/sockets to be at different heights + distances apart?

FaceHead

It's done now, so there is little you can do. If you are really unhappy with it then modify it yourself, otherwise chalk it up to experience. 

I think there are two lessons here, which it also took me my first whole renovation to learn:
- Some trades are fools, and some are excellent, but you don't know which the person in front of you it. You therefore need to tell them things that you think are obvious, e.g. this lightswitch inside the lounge door, to be at the same height as this existing light switch in the hall just outside the lounge. You'll almost certainly get funny looks, but it's better than the occasional fool who does it at some other height. 
- If you want it done exactly how you visualise it, you need to do it yourself. If you're not prepared to do it yourself, you need to accept some deviation from what you'd have done. Sometimes, though, someone will do it not quite how you visualised it and it will be better than what you had in mind.