You can find details of that penalty system here (opens in new tab), but essentially, expect to be fined currency or experience of an equal value to the match you abandoned/didn't do anything in (with a few exceptions, explained in the linked post). Also in the update: more higher-def vehicle models, balancing, and improvements to the newly implemented (opens in new tab) Strongholds mode. You can now employ Legionnaires (these are players unaffiliated with a clan), and construct a War Department, i.e. "a building which will give random quests" to your fellow clan members.
Here's all that again, in video form:
Ta, PCGamesN (opens in new tab).