It should work fine. I have often wondered about trying other mosses because we are surrounded with huge amounts of moss here, especially in the winter. I can't seem to find any sphag growing wild, and it is hard to find in the stores here. It seems a shame to pay for moss when it is everywhere I look.

I think you have an excellent set up. The important thing, now, is just to keep an eye on your orchid to make certain it adapts. Any time you change a plant/orchid's culture, it is wise to do this. If your orchid isn't happy, you adjust but I'm guessing your orchid will be perfectly fine. I have seen countless pictures of phals and other orchids successfully being grown in different ways (vase culture, hydroponics, semi-hydroponics, water culture, mounted, in bark, in moss, etc). Different things work for different people. Good luck!

Yes. Set up looks good.