How to refurbish a 2 bedroom 1930's semi

Hi, I am buying a 1930's 2 bed semi in Balby area of Doncaster. It is due for some refurbishment, although it has been lived in up till recently by an elderly lady and is in relatively good order. The electric fuse box is of the old fuse wire type. The central heating boiler is quite old, it is said to be working well though. The hot water cylinder is not polystyrene insulated, having lagging jacket and water tank above. The bathroom does need to be updated and the kitchen - I would like to move the kitchen units/cooker and sink to another wall, but drainage is still available. I would like to refit the downstairs toilet - it is next to the kitchen, - moving the fittings somewhat to give better access, new door and stud wall to be built. The house roof is slate and not felted. I would like advice on enlarging or moving the loft access as it is tiny at present - could I board the loft for storage, should I put in a Velux window? The walls are cavity insulated and the gutters, fascia and downpipes are new. Access to services does not appear to be a problem. I expect to complete the purchase in the next 2-3 weeks hopefully, and do have limited funds - what should be my plan of work? If I am unable to do everything at once should I leave the roof and felting? Should I concentrate on the plumbing and electrics - if so, in what order? Thank you.