How do I bathroom / kitchen / extension? etc.

A penny for the hive mind's thoughts...

In the process of buying a 3-bed mid-terrace that looks a bit like this (first time using sketch-up), with possible plans scribbled on as follows (in addition to general renovation/updating):

• move boiler from upstairs bedroom to downstairs utility
  
• open up kitchen (90s extension) to dining room
  
• re-arrange kitchen so that it flows along the length of the opened up back wall, with hob tucked in the chimney breast (once opened up)
  
• can't see it, but i'd also like a skylight in the current kitchen's roof
  
• some kind of semi-glazed double doors between dining and living room
  
• possibly moving the downstairs loo underneath the stairs, but not sure if that's not more work than it's worth (especially if boiler goes there)
  
• shift upstairs wall (non-struct.) back to original place (3rd bed will be an office, long-term plan to convert loft to 3rd bed proper)
  
  

Any major flaws in those plans? Things you'd do differently, or better ideas?