Thursday evening / Train
Indeed, coming from Mainz some trains also stop at Mainz-Bischofsheim, Mainz-Römisches Theater etc.
--> BUT: leave at Hauptbahnhof (Main Station)
For saving money: Take a local train and not the IC or ICE, but takes a bit longer, 10 minutes I guess....
Just fixed the meeting location for Thursday evening:
Who wants to join us before the event on Thursday evening for dinner/beer/wine... we will meet at 7pm at Proviant-Magazin, Schillerstraße 11 a, 55116 Mainz. There we have enough room to sit in or out depending on the weather. It is very central and in walking distance of the hotels.
Look forward to our event,
No I have no idea about this, you can get a answer from google.