Is this West Elm sofa the kind of thing you are looking for? Or even lower to the ground? http://www.westelm.com/products/4227534/?catalogId=52&bnrid=3918508&cm_ven=Google_PLA&cm_cat=furniture&cm_pla=Sofas_+_Sectionals&cm_ite=West_Elm_Baxter_Sectional_Sofa_Cotton-Rayon_Ikat_Print_Feather&adtype=placi_src=17588969&ci_sku=4227534&ci_kw=%7Bkeyword%7D

based on the drawing, the wall where the bed is. HOWEVER, you mentioned that this drawing is not a true depiction of the furniture you will use and the wallpaper. if that is the case, i think the wall paper can work on either wall, it all depends on how busy this wallpaper is and how "plain" the bed is. if you go with a busy wallpaper behind the bed, you may want to keep your bed and bedding on the minimal side so that there is a good visual balance to the overall composition. if you go with snazzier bedroom furniture, then a busy wallpaper may be a bit much and you may want to put it on the other wall or use a textural option to serve as the bed's background rather then another focal point.

I recently saw this episode of Ask This Old House where they demonstrated painting tiles - especially as a solution to get one through till an entire redo is possible. http://www.thisoldhouse.com/toh/tv/ask-toh/video/0,,20902001,00.html Looks like you are doing a great job!

It's great to see professionals consider sustainable options