Hi,
I would recommended, for the most robust design, to follow the unused pins recommendations in Appendix C of the Hardware Manual which is available from the design support files (http://ez.analog.com/docs/DOC-1712).
In terms of how to handle multiple pins which must be terminated through resistors, I would recommend, for absolute safety, to tie each pin to an individual resistor. This should eliminate any possible ESD risks of tying multiple pins together.
Joe