Rawblin

This can be done via an FTP client (Like Filezilla) The credentials to get into your server with this are on your control panel webpage, under "FTP Details". *SHUT DOWN your server before copying these files to your desktop!*
 
Input the info into the correct fields in Filezilla, connect to your server, then navigate just like on a normal computer to /ShooterGame/Saved/SavedArk##### and simply drag and drop (or right click and say download) TheIsland.ark to your computer, along with any and all of the ###.arktribe and #########.arkprofile files in there. These are your tribes and players characters, respectively.
 
That is the barebones version of saving your map and tribes/characters.
 
If you want the super easy version (that takes a lot longer to download and a lot more diskspace), simply copy the "Saved" folder under /ShooterGame/ to your desktop. This includes all of your configuration files as well as all of the backups the server has made of your map and players/tribes. 
 
Once this is on your desktop, you can safely delete the SavedArk##### folder from your server in the FTP window. Switch the map on your control panel webpage to "ScorchedEarth" or whichever you like, and then click "save and restart" at the bottom.
 
When you want to boot your server up with this map/characters again, simply shut it down, back up whatever you currently have in your Saved folder, and then replace it with your Island version of the Saved folder.
 
I think that fully covers it, but that's just off the top of my head so let me know if you run into any issues.

You said you read plenty of the other topics on this in here, but they explain exactly what you are asking.
 
First, make sure you have [server Settings] in your GameUserSettings.ini file.
Then underneath that either create or change DifficultyOffset=1.000000 to 5.000000 or whatever you wish.
Then underneath that either create or change OverrideOfficialDifficulty=5.0 or whatever you wish.
 
Save the .ini, send it to the server via FTP, then restart the server. Once the server is running again, you can either wait for dinos to be killed and the new spawns will be the proper level variance, or you can wipe all dinos on the server (which usually crashes mine so be prepared) with "admincheat destroywilddinos", no quotes, in the console.
 
And voila.

Interesting, I thought this was just a cluster error! I'll see if anyone has let the Structures Plus creator know and if not I'll give him a heads up. Maybe it is fixable!