I have 3 and 4 ladies at a time come to my home and we do all sorts of projects. I have a Viking Diamond, one lady has the same, another has tol Bernina and one has an older Viking that uses floppy discs. We all learn from each other and help with hooping, etc. Someone brings snacks (apple fritters are my favorite!) and we usually go for lunch (only a few minutes out of our day as I live "in town"). We have a great time tho truth be told I don't really get any projects done, I am busy helping everyone else! The lady with the Diamond leaves it here at my house and she is really not comfortable doing things by herself. We were meeting once a week, but I had to put it on hold until I finish 5 prom dress alterations!
I have given some 1 on 1 lessons in the past, and they were well received. Some newbies just aren't aware of all the stabilizers and products required to actually do a design! I spend a good amount of time on procedures and different ways to do things (hoop with blue tape, spray adhesive, multiple hoopings, etc) before I actually hoop an item and start stitching. I enjoy helping get a new person started...seeing them with a first finished project is wonderful!
The hardest part of having a guild IMHO would be having to drag the machine to and fro, with all the supplies, etc. If you are only meeting to share ideas and show and tell, it might work well. I am not willing to pack mine up!