Could your Jewel Orchid be the species Macodes petola?
I'm not an expert on fungus or mycology, but if it isn't killing your plants or harming it, then it is probably helping it grow.
It's probably acting like a mycorrhizal symbiont in the fern's roots.
Mycorrhiza - Wikipedia, the free encyclopedia
The mushroom you've posted a picture of is most likely in the phylum Basidiomycota. The underside of it where the gills are are where the spores are formed.
Basidiomycota - Wikipedia, the free encyclopedia
What you're seeing is the fruiting body or basidiocarp (in the case of fungi in the phylum Basidiomycota).
The non-fruiting part of the fungus is microscopic and forms a web of mycelia in the humus.
Mycelium: the mass of hyphae that form the vegetative part of a fungus - (mycelia is the plural form of the word mycelium)
Hypha: (in a fungus) one of the threadlike elements of the mycelium - (hyphae is the plural form of the word hypha)
The definitions of hypha and mycelium are from Dictionary.com.
The snails on the other hand I don't know too much about. They could eat parts of the plant. It depends on the species.