It doesn't sound like you are worried about ever getting your money back for the improvements that you make. If that's the case then go ahead. The picture window can be done by a good carpenter. I think the wallpaper is the plastic stuff that is bonded to the wallboard under it. There are many, many posts on this site regarding trying to do something over it. If it's this type of stuff, removing it will be mostly impossible. If it's actual wallpaper then it might be able to be removed.
Floating floor...I know nothing about them.

Coolvet - I appreciate your feedback thanks. In considering your comments, I would like to modify my post - I probably will be in the home for about 10years (not 15). I don't know how quickly my very rural area will become populated; currently there's little in ammenities - muncipal or retail.

Also, I am worried about getting my money back.

I know we can't forsee the future, but don't want to 'invest' my retirement fund unwisely (not looking for investment, just word choice....)

Again, thank you

If your home is on a foundation and not piers you should have little trouble recouping your money. Just maintain the rest of the home and I see no problems. A floating laminate floor is a good choice and the larger windoe seems like a good idea. Go for it.
FYI, double wides on a foundation are going for around $175,000 to $200,000 around here.