I am still using the old 18.104.22.1681 version because I have no need for the extra stuff they put into the latest versions but this is how my window looks:
I do not know to which extent this can still be done in newer versions, but the way I did it on the version that I'm using was by going to the "Messenger" menu >> Show/Hide >> Unchecked everything but "Status Chooser" (for an even more compact view, this can be unchecked as well). Basically, a lot of stuff can be either disabled or hidden to make the most compact view possible.
For the annoying ads (I mean, seriously, forcing animated, flashy ads on a user's desktop ?!), I used a batch script (noYMads) that does the required modifications automatically, but for your version, doing a quick search on Google will give you plenty of options. One that popped out and looked promising is Ad Banner Remover Plus.
Also, just in case you're interested in this older version, it can still be found on oldversion.com.