Re fault 1, whoever fitted a fuse of double the original capacity obviously did so to try and cover the fault, and as you say this has probably in time burnt something else out.

A bit of time with a meter should find the headlight fault if you know what readings you are looking for, electrics arent my thing past basic continuity tests etc so I tend to get someone else to have a look.

I think the radio's are coded so before pulling the power for a re-set see if you can find your code, I think mine is written inside the service book.