Unfortunately, the best way to get your gear to work properly is to add a proper 5.1 speaker system which should be connected to the Pioneer receiver. Dump the soundbar. The Energy Take Classic 5.1 system is a good entry level 5.1 speaker setup you should grab. Anything else, including using the Xbox as a 'hub' will be a kludge with certain features/functionality always missing. You could however continue to utilize the Samsung unit as a 3D/BD player.
This is my 'recipe', even not knowing the specific DTV receiver you are working with. Take it or leave it 
Samsung BDP (HDMI out) --> (HDMI in) Pioneer
Xbox (HDMI out) --> (HDMI in) Pioneer
DTV receiver (HDMI out) --> (HDMI in) Pio
Pioneer (HDMI out) --> (HDMI in) BenQ projector
Pioneer ---->>> Energy Take Classic 5.1 system (or equivalent)
FWIW, the Energy Take Classic 5.1 (~$300) will sound much better than the Sammy system you have now. You also might use Amazon's liberal return policy to compare with the Yamaha 5.1 system I see they have on sale for $134- less than half the price of the Energys. It definitely won't be any worse than the Samsung, which is nothing special. Look here:
https://www.amazon.com/Yamaha-NS-SP1800BL-5-1-Channel-Theater-Speaker/dp/B001AVRD62/ref=sr_1_9?s=electronics&ie=UTF8&qid=1470250242&sr=1-9&keywords=energy+take+classic+5.1
Let us know how it goes.
So here is what I have. Obviously not everything is hooked up. I currently have:
1. BenQ HT1085ST Projector
2. Xbox One
3. DirecTV
4. Samsung 5.1 3D Blu-ray Surround Sound System (AH63-02256B)
5. Pioneer - 700W 5.1-Ch. 4K Ultra HD and 3D Pass-Through A/V Home Theater Receiver (VSX-524-K)
6. Samsung Soundbar (HW-HM45C)
I currently have the DirecTV going to the Xbox, the Xbox to the soundbar, and the soundbar to the projector and everything works fine. My Xbox powers the whole system and acts as my Blu-ray/tv/Netflix/gaming. However, I want to set up the 3D Bluray 5.1 Surround Sound. The sound is so much better and I can watch 3D movies. The logical thing would be to just swap out the soundbar and the 5.1, but the 5.1 has no HDMI Inputs. Just the output to the projector.
Is there any way to get all sound through the surround sound speakers (including normal TV sound) with the devices I have? The big issue with the 5.1 is that the optical input doesn't really work. It is missing a small metal piece that holds the cord in place. So it loosely just sits in there and if there is a slight breeze, it falls out. However, I'm sure I can do something to keep it in place if someone has a solution.
The other issue, is that when I have the DirecTV going through the Xbox One as is, the Satellite comes in perfectly. But when I attempted to plug the Xbox into the receiver (with DirecTV still in Xbox) I got an error message that said,
"Your TV does not support this program’s content protection. Replacing the TV’s HDMI cable with component cables will allow you to view the program."
But when I plug the DirecTV directly into the Receiver, it works fine. So not sure what that is about, but I'd like to keep it going through the Xbox if possible so I could keep it at the same input/source.
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