Welcome to ld4all Floater, you will find a big sticky topic about shared dreaming here [The Big Shared Dreaming Topic-Part 2)
I personally believe shared dreaming is possible as a form of telepathy. At the SeaLife forum quite a few members of dream teams are trying to meet up in their dreams.
I hope you find all the answers to your questions floater. 
I’ve moved this from the diary section to “Quest for Lucidity” (since your questions covered so much I had to decide between this section and beyond dreaming)