The whole idea is for the switch to achive logic levels, and
thats its internal R x leakage will not exceed the logic state
trying to be achieved. So you dont need R's.
But I assume when in standby you have to terminate the input
to a valid level related to coin cell operation ? Is the 5V present
when coin cell is backing up ?
If 5V disappears then any input switching has to be to coin cell
rail. But when 5V reappears your pullup value has to go to highest
rail. That can be handled with diodes.
You might consider a R to ground at input, and a SPST switch from
input to + rail. R would be simple. Calc to absorb leakage and then
drop or Vin << .8 V for TTL. So switch open R pulls to ground,
closed swicth pulls input to V+rail.
Lastly does switch need to be debounced so a clean signal occurs
on input ? If so
http://www.eng.utah.edu/~cs5780/debouncing.pdfRegards, Dana.