I've managed to get the OpenVPN connected now. It appears the issue was at the OpenWRT/OpenVPN end (due to my inexperience with it).
I didn't use the bare config file but rather the "wizard" (if you can call it that, its more of a text entry box). This is the correct config needed on the OpenVPN end:
option dev 'tun'
option keepalive '10 60'
option verb '3'
option persist_tun '0'
option persist_key '0'
option port '1194'
option auth 'SHA256'
option cipher 'AES-128-CBC'
option enabled '1'
option secret '/etc/openvpn/dcvpn.key'
list route '10.94.43.0 255.255.255.0'
option ncp_disable '1'
list remote '12.64.66.45'
option comp_lzo 'yes'
option ping_timer_rem '1'
option proto 'udp'
option ifconfig '10.94.32.2 10.94.32.1'
And pfSense:
verb 1
dev-type tun
dev-node /dev/tun2
writepid /var/run/openvpn_server2.pid
#user nobody
#group nobody
script-security 3
daemon
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
proto udp4
cipher AES-128-CBC
auth SHA256
up /usr/local/sbin/ovpn-linkup
down /usr/local/sbin/ovpn-linkdown
local 12.64.66.45
ifconfig 10.94.32.1 10.94.32.2
lport 1194
management /var/etc/openvpn/server2.sock unix
route 10.94.48.0 255.255.255.0
secret /var/etc/openvpn/server2.secret
compress lzo