Hi, if you're using automix in dual-deck mode, there's nothing stopping you from manually loading tracks while automix is on.
So the answer to the second question is simply turn on automix and manually load tracks onto the decks.
The answer to the first question is a bit different.
When automix is on and tracks are loading automatically, you can check which deck is paused at any time with the F1 and F2 keys. Then, load a track directly there, at will, from the file panel or the side list.
When the automix finishes playing on the opposite deck, it will automatically switch to your track.
You just need to be careful: when a manually loaded track ends, the automix will automatically switch to the opposite deck, but it will start playing the automix list from the top, so tracks may be repeated.
The first option is to, before the automix finishes the manually loaded track, go to the automix panel and load a track that hasn't played yet onto the opposite deck. Then, the next tracks from that list will automatically load. The second option is to enable automatic removal of played tracks from the automix list, which will always have a new track waiting at the top of the list.
The third option is to enable randomization of the automix list after each track.
You can find the appropriate options in the Mallmuzik/VDJ options menu, or by pressing the "o" key in the automix panel and using OCR in the context menu.
For some reason, my automix uses decks 3 and 4, so pay attention to which decks you're using when loading tracks.
To get my automix to use decks 1 and 2, I first press Ctrl+Alt+d to select dual-deck mode, then I enable the automix, which uses decks 1 and 2.
Best regards, Zenek