The switch on the front of the amp only affects the lower row of terminals, marked 'switched'.
For the TDLs, just use the top row of speaker terminals, unless you want to be able to turn off the speakers, for eaxmple when using headphones, in which case you'd use the lower set.
If biwiring you could either use cables commoned into one set of plugs - ie the left HF and LF 'red' cables are terminated together in a single red plug at the amp end, and so on, then just use the upper 'direct' terminals, which sound a shade clearer than the switched ones, or use separate cables from amp to speaker, in which case I'd use the lower switched sockets for the bass. And of course switch the terminals on using the front-panel control.
To biamp you'll need to add a power amp, such as the 8000P.