Rhendak

Here's how to set a tag once you're ingame.
Press TAB > Right click to have your mouse appear and go to the "cog-wheel" settings icon. Then in the settings you will find a setting named "player tag", after that you can enter what you would like to have as playertag (in front of your name), you can even set the color of your player tag!
Here are the rules regarding playertags and names: http://forum.ets2mp.com/index.php?/topic/15-in-game-rules-en-11-08-2015/

Please refer to this topic: http://forum.ets2mp.com/index.php?/topic/20371-old-name-showing-on-ets2mp-map-web/

As mentioned above (which I felt could use a bit more clarification), there is a speedlimiter of 60kmph within cities. This is added by the multiplayer mod and it works a bit like non-collision zones. As long as you are within the speedlimit-zone (which is only in/near cities), tje multiplayer mod won't let you go faster then 60kmph. There is no setting for this and you can't turn this off.
Outside of the cities, the maximum speed is 110 (this does require you to have the base speedlimiter of the game turned off in the gameplay sections, otherwise you won't go faster then 90kmph).
I hope this cleared things up a bit for you.

Yes you are. However for the high value cargo pack and all the paint scheme DLC's, you can't see them on other players if you don't have the DLC yourself.

I think this is something related to the game itself rather then the multiplayer. From what I know this can't be changed by the multiplayer. If you want this to change, perhaps suggest it on the SCS forums. 

The AI (also known as NPC) drivers you can hire ingame because it's part of the original the game. As far as I know, these were also bugged in the multiplayer. Meaning you only earned cash from them upon logging in to the player but they then wouldn't work until you log in again. I'm not sure if this is solved by now.
 
 
Next to that you have VTC's, which stands for Virtual Trucking Company. These are often clans of players who enjoy this game together. As it's a Trucking Company they also often allow you to submit your jobs in their VTC panel, as that adds to the realism of being a company. You can start your own company or you can choose to have you and your friend both join the same company. A full list of the VTC's available can be found here: http://forum.ets2mp.com/index.php?/forum/43-companies/
 
I hope this explanation helped you and is clear enough for you.  

Since One Two is a member of my company, I sat down to help him for a bit (about 2-3 hours).
The problem was solved. The following has been done to solve this problem:
- A system clean - (Ccleaner, Anti malware bytes, ADWCleaner, non-used programs/games deleted, installed a virus scanner)
- Harddrive was split in two partitions. C & D.
- Steam was fully uninstalled and reinstalled on the D partition.
- The ETS2 documents folder was fully deleted & renewed, except for the "profile" folder inside it.
With that this topic is locked and solved.

Press F7 + ENTER. This should fix your issue.

Please make sure your installed OS has the right codecs to play the music. I'm not sure exactly which codec you need but I had this problem before with running the N-edition of Windows. In that case installing the K-lite codec pack or Windows Media Player solved the problem.