I figured out loaders are not mandatory after I opened the stock UT:XMP maps, but I added one for trial and error anyway. Couldn´t hurt.
The default gametype is set to XMP.XMPGame and was set like this the whole time. But I just found out that theres a "PreCacheGame" that is set to "xGame.xDeathMatch" by default. I´ll change it to XMP.XMPGame now and give it a try. My guess would be that´s the problem.
And I used deploy points not player starts.
Some basic information:
-Two nodes including Artifacts (correct setup; they work fine)
-Three generators (correct setup; they also work fine)
-Six deploys; two for each team and two neutral (IMO correct setup but the weapon "bug" thingy)
Thanks for the help so far guys, you are great.
Edit: Okay, the PreCacheGame thingy didn´t work either I guess, because I still spawn with the Tech Assault Rifle instead of the Shotgun. It´s nearly 4am now and I don´have anyone to test it with me til tomorrow, but I found out that if I spawn with the AR instead of the SG it´s not workin and still the host is the only player with weapons. It´s pretty discouraging if you can´t test the gameplay due to missing weapons though. I can only guess what it would be like for now, but hey I still got lots of work to do with lighting and positioning static- and team-meshes, so I´ll be patient and wait for more possible solutions for this particular problem...