Safety Equip. Placement ? Casita 16'

[partslady9]

I mounted the smoke alarm at the side dinette overhead. For the fire extinguisher I have a small space at entry door under the front couch/sofa, door hinge side - my hubby thinks it will be too much in the way,(he is not an egg fan) I think it will be handy if needed outside. 2nd choice is partition wall between dinette & front sofa. any suggestions? There is a small 12x12x6 cabinet on this wall so f/ex. would be somewhat hidden.I purchased a c02 detector but reading fine print said mount 20' from any source (oops). Should I purchase propane detector?
Any suggestions would be appreciated.
Elaine