Guten Tag Dominik
> As soons as I try to add Symbols to a second layer the ...Once you have created the new layer you have to make it active. This is the equivalent of selecting a physical layer on the map which you choose for editing. You can do this by clicking on the layer:
--> The pen icon should be visible. This way, symbols can be placed on the selected layer (+ icon is active again).
> I have got one additional question: Is it possible to request to add symbols wich are not yet included?
We strictly follow the MIL-STD-2525C to provide the baseline for interoperability. Hints:
1. Did you use the 'MSS Symbol Search' function for Military Symbols? The 'Symbol Gallery' only list a small sub set of the symbols (~15%).

2. Did you check the Extended Mode?
