I know nothing about fire suppression plumbing, but that fixture in question certainly resembles a back flow prevention device. If it is, it not DIY...
I've seen two typs of faucets for the stand alone bidets. Does this one outlet below the rim then?
The second style has a faucet that is on the top,...
I think many folks are under the impression that installing a toilet is very complicated and therefore beyond their ability. This really isn't true....