Browser goes to http://localhost:8085/apex/f?p=4550:1:5614682097186 and displays a blank pageThat's usually the case when you didn't configure your APEX "images" (static contents) properly...
1: Why is the default URL going to somewhere that doesn't load a page?The page is usually loaded, but you don't get usable content because your static contents can't be served as needed, so you miss all css, js, images and stuff needed to render your page. Take a look at the page source (contents) - you'll probably see more than you have on your screen.
2: Why, when I manually go to an actual page does it load without a theme?It is related: It's because the static contents for the theme is not there. (see above)
Is there any way I can enable some more logging on the listener to help try and figure this out.I guess you won't need to.
Can you tell me how I can get the static content from the database server?Your question can be answered easier if you knew where your current web "static files" are located.
We have some custom themes used in our application, so I'm assuming the best way to get these is to get the current set of files from the server.
I've tried getting the directory $ORACLE_HOME/apex/images and passing the path to a local copy of this directory to the standalone listener, but I get the same result.