More or less the first part only - another poster dug up this link, which should help:
http://www.microsoft.com/en-us/download/details.aspx?id=21464

Basically, certification checks that it works on all xboxes, has a certain level of game stability, and obeys rules about naming conventions, accessing gamer profiles, sharing of achievements, and other standards and requirements for the console. For example, load times have a maximum amount of time allowed - exceeding that time is grounds for failing certification.

Microsoft does not QA your game, send you gameplay feedback, or otherwise replace a certification department - that is the responsibility of the developer and/or publisher to front, depending on their contract and relationship.

Vancouver actually had a proposal to do exactly this, as well as to include cell tower coverage and potentially a few other types of data.
http://news.nationalpost.com/2012/05/22/douglas-coupland-created-v-pole-may-take-high-tech-to-the-streets-in-vancouver/

"The device, no larger than a telephone pole, would manage cell signals for multiple carriers, as well as wireless Internet for the surrounding neighbourhood. In-ground pads plugged into the pole would provide inductive charging for parked electric cars. An integrated touch screen would display maps, ads or payment interfaces, and an LED street light would be perched at the top of the pole."