SRAM Omnium crankset

HELP! (Or, great condition Omniums for sale...)

Used (but great condition) Omniums, new GPX BB, new chainring, new chain, new sprocket, old and abused Fuji Track. Fitted in October, and ridden every day since but never without an issue.

• the cranks need re-tightening every 6-10k on the road, to the point that I even carry a full sized allen key. Next step is too get the frame re-faced, but any other suggestions on why this might be happening?
  
• Hit a pothole yesterday, one heavy clunk later, and I've got some serious clicking issues which I hoping might be BB related (see linked video) but has anyone else come across similar?
  
• Cranks definitely do not turn freely (see end of linked video)
  
  

Anyone have any thoughts? Please let me know if I've missed any important information or worse, missed a relevant comment at the top of the thread - I'm sort of hitting my limit and considering a return to trusted square taper!

https://vimeo.com/126398056