For MAC Address,
you could get one with Inventory > Search with various criteria and choose 'Local/Networks' table, field 'MAC address'. (But you get only one MAC address ... for me in 2.6.0)
Using SQL, you can look table 'networks' : for example
select h.name, n.description, n.macaddr, n.status, n.ipaddress, n.ipmask
from hardware h, networks n
With this sql query, you'll get all MAC address for each hardware (and only for hardware having a MAC address).
Please note MAC address could be forged, and maybe non unique (rare but exists for enormous set) ...
(For my company, we use linux firewall with vlan = on each interface (eth1.51 for vlan 51), this is the same MAC address from OCS agent, ... but same hostname. So I'm not sure the MAC address is an unique identifier !)