I see at least one flaw with the plan to mix cyanotype chemistry with paint. I don't see how you're going to wash out the residual (unexposed) chemistry once the exposure is made. Coating on canvas or muslin and making "wallpaper" would be the way to go. (To coat large swaths of fabric or paper, artists usually mix up gallons of cyano solution and then submerge the substrate in the solution using buckets, drums or large tubs.)

I suppose you could try this:
* Coat the wall with gesso (or similar)
* Apply a coating of cyanotype solution
* Expose
* Wash
* Coat with clear varnish or polyurethane

Of course, making sure you don't flood the place is of primary concern. You will have the same issue should you attempt the Lumi Inkodyes.