Is the maximum properties value for a class the total amount of properties they can have or is it a limit for the highest properties value that a single equipment or ability can have?
For example, is a level 2 humanoid class (Maximum Properties 2) able to take a shield, martial sword, and flintlock pistol all together (each with a properties value of 1) - or can this class only choose two of those items?
Properties is a limitation per item or power. So yes you can take the shield, sword, and pistol.
Properties is a limitation that can be increased in several places often as a class option. In general Properties equals the level of the class (without any upgrades).
Not only is it a game balancing factor during campaign play (as your faction classes gain new traits), but its also a factor difficulty to use or training to use. So you will find that the Fey for Instance better bonuses to properties for powers while humanoids can get better properties for equipment.
I am wrapping up the gameplay video today so it should be ready to go tomorrow. It will be posted on our Kickstarter page as well as on Facebook and Youtube.