I go to VIM and think its pretty reasonably priced and not too crowded tbh. I also go at ~6:30am though

You should certainly buy your own router. I would be shell shocked if you got xfinity for $30/month, even if they advertise at that amount. They are scumbags to the maximum and will sneak in additional costs. Plan for $50-60/month at least and be pleasantly surprised if it is less.

There is no set up cost, Eversource will just start sending you monthly bills starting one month after you set up the account.

Comcast for just internet (no cable) will probably run you $60-80/month. Electric its impossible to guess without understanding your square footage and if you have gas or electric heating. Good luck!