Due to the chilly winter months, all events will be held indoors. The parking lot has gravel though, so keep that in mind while picking out your shoes!
If not a Santa Claus outfit, then whatever you're most comfortable in. In general for weddings, I aim for something I could wear to a nice dinner or to a graduation. Its a hard line to draw, but at the end of the day we just want to see your faces no matter what you wear!
A quick google search says Cocktail Attire/Semi-Formal is the phrase that best fits.
Other than some reserved tables for family and wedding party, you can sit next to whoever you want to! There will be plenty of long tables as well as seating up in the lofts for you and your pals to sit together.
I sure hope so!