Welcome Fionhun
Regarding the building work you need to do ,How good are you at DIY ?
have you attempted any of these jobs before ?, except the boiler/ Electrics as by Law you cannot touch them now ?
If you or partner are competant Diyers then the other jobs ,
new kitchen, new bathroom & polystyrene tiles removed from ceiling
arent that hard if you get good advice ......
Knocking the wall down is not that hard BUT YOU MUST make sure its NOT a load bearing wall , its a very messy an dusty job ..
Im sure you will find a good post about this in the builders section here ,
the new kitchen , go down an see the posts in this section with pics
a new Bathroom ,again many posts here in different sections to read up on others diy jobs ,
polystyrene tiles
is just a case of a wallpaper stripper scraper an "elbow grease"
If you have specific any problems ,Please post in the individual sections
cheers