I am going to run all these little wires into 1 wire, probably 10G... and run that straight to the battery or Chassis. It's ok for them to share a single ground cable isnt it? For guages and an alarm?

As long as none of the grounds are “switched “ grounds from the alarm. What I mean is with the alarm activated the wire will turn negative and with it disarmed it’s open. There have been insistences where a back feed situation occurs. This is easily corrected by using a diode “ they limit current flow to one direction depending on which way they are installed. I would try and hook it up the way you are talking about using a distribution block, then test each feature and make sure they function correctly. Otherwise sharing a ground location is a common practice and makes for a much cleaner install.

Thanks, you got to me right in time, Im heading home to hammer down on my alarm more and prep everything for my solinoids :D Too bad I have to work tomorrow.... ah