Yes, I have the ER4 with the SFP mentioned for my fibre7 connection in use. It works perfectly. With regard to HW offloading, not much seems to be activated for me. But as far as I know, I have never actively configured it... Since I have no problems, what is activated seems to work. The following are my settings:

$ show ubnt offload

IP offload module : loaded
IPv4
forwarding: enabled
vlan : disabled
pppoe : disabled
gre : disabled
bonding : disabled
IPv6
forwarding : disabled
vlan : disabled
pppoe : disabled
bonding : disabled

IPSec offload module: loaded

Traffic Analysis :
export : enabled
dpi : disabled
version : 1.480

Yes, yes & yes :)