You can give the named resource agent a user via 'named_user', and you can pass other options via 'named_options':
pcs resource create NameService named named_user=named \
named_options="-t /var/chroot" op monitor interval=30s
Or you could try using the "anything" resource agent to feed options to named. It would look something like this:
pcs resource create NameService ocf:heartbeat:anything \
binfile="/usr/sbin/named" cmdline_options="-u named -t /var/chroot" \
pidfile="/var/run/named.pid" op monitor interval=30s
EDIT:
For more resource agent options:
# pcs resource describe ocf:heartbeat:named