I'm setting up my beofeng for a universal use kind of radio that is optimized for use in an emergency (scanner wise).

I am setting it up as follows so far:

1) 7 weather stations, duplex off, skip scan

2) local frequencies, repeaters, anything I'll use or talk on when I get my license, these are on the scan list

3) local police, ems, fire, public services, duplex off, these are on the scan list

4) local businesses I may want to listen to for funsies (as well as where I work), duplex off, skip scan

5) MURS, skip scan

6) FRS/GMRS, skip scan

I don't intend to transmit on anything I'm not legally permitted to, or for that matter anything at all at the moment. I do want to be able to listen to anything though.

Are there any universal frequencies for 2m/70cm, or any uhf/vhf bands for that matter that I may want to monitor for an emergency?

are there any frequencies that are used as a "community gathering" such as ch 19 on cb is used?

in other words, if you want to just get on the radio and find someone, anyone, where would you look?

One idea that isn't illegal at all is to find the local RACES/ARES frequencies. These people frequently are on the spot when SHTF and may be able to alert you to where not to go.

for example, one deployment as a LASD RACES ham was the Rodney King riots. About the 3rd or 4th day, things had calmed down such that I could go to the local sheriff station and staff the ham station there.

I learned about a fairly major disturbance about 30 miles away that was blacked out by the news media!

You may want to include the 2 meter simplex national calling frequency of 146.520. And also the 70 centimeter simplex national calling frequency of 446.000

If the radio is part 90, then it's actually legal to use with a business repeater.  I found the DCS code for ours.  The license specifies a certain number of radios that can be used at a location, and their wattage. 

This,  and there may be a frequency that is in common use in your area for simplex use.  Here it is 146.500 on 2-meters.