1 yes DTS is set correctly on the advance device settingsI don't know this SB software, because I don't own a SB card. You could first look for yourself.
In (1. picture) Windows device properties -> go to "Device advanced settings", if DTS-C was setted correctly.
In (2. picture) SB-C app -> go to "Settings" and look for a 5.1 option.
Do you have a 5.1 source for trying out real audio test?
If not, try this: https://www2.iis.fraunhofer.de/AAC/multichannel.html
2 the only option that I can choose is stereo, the 4.0, 5.1 or 7.1 should be shown aside the stereo one but in my case it's not like that
Yes I have some blu rays and movies with multichannel audio that when played emit sound from all the speakers not only the front ones, but previously I remember getting surround sound from music player and games, not only in 5.1 encoding sources like multichannel videos, dvd's or blu ray's, I don't know if I can set up something in the tweak tool to get it working again hehe.