Ok if u are not registered, and u are replacing like for like than u would be ok, but if u are extending any ccts or modifying u will need a minor works cert, inform LABC, RCD etc
You will need rcd protection for the proposed lights in bathroom...............As the board is an old wylex 3036 type, u could get round this by running the bathroom light cct through a RCD FCU (placed in the airing cupboard possibly so its accessible) labelled correctly with the correct fuse etc. Test bonding to check that it is less than 0.05 ohms or less As per GN3.
To be honest the kitchen light cct is no longer a special location so would not worry about this too much.............Ask yourself is the job worth it to u really if ur not registered etc? I.e what ur gonna make for the hassle etc?
Why the sudden change for all accessories in the house? is it just a cosmetic thing?