Are you using a Mac by any chance? If so, place the items.cfg into Feralheart\FHRoot and click replace instead of the main Feralheart folder. If you aren't using a Mac, then make sure you take a look at Echoz advice above. Good luck! :)
I have the same issue with using ANY kind of texture, custom, marking. Anything, none of it shows up in my menu and very rarely can I see stuff on other people and it frustrates me to no end. I'm using a mac and I would very much like to use my custom (when it's done) I've followed all the instructions. When I look at the 'presets' in game it doesn't come up with any 'preset1' or anything. It's just blank (I can't log in and screenshot as I'm -coughs- in trouble)