Microwave is definitely 110v and uses quite a bit of power. It could run off an inverter but you'd likely need larger batteries to support use and have remaining 12v to power everything else. If you have or you add an inverter, make sure it's output will meet your needs (I'd think minimum size would be 2000 watts for the 'wave).
Those built-in vacs are pathetic gimmicks. An inexpensive Dyson cordless is superior. Not sure if 12v or 110v, so just plug your trailer into an extension cord from the house and try it ( if you don't have the adapter to use a regular house outlet, get one, everyone should have on in their kit).