Oh, I tossed out the MGs . . . and while I dislike MRMs as well, relegating them to combat engineer units that need to re-arrange the battlescape . . . A Avatar with 2 MRM30, CASE II in a side torso with the ammo, C3 slave, ECM and a few DHS would work with a dedicated C3 force IMO. Of course it would be better facing the FedSuns than the Ghost Bears, and would try to keep at 11-15 hexes while the spotter was at 5. My casual dismissal of MRMs is why I looked a bit closer at the idea- primary goal being to pepper it with damage and force a PSR.
IMO if its a private Omni, its maintenance and access to pods would be similar to a private standard mech employed in House service- namely that as long as it is a authorized/ordered action the House will be responsible for repairing & replacing equipment. Daddy bought you a Black Hawk KU upon assignment to 1FSACR after graduating NAIS, and it was fitted as a OE when you showed up for duty then the AFFS is responsible for the maintenance of that unit within the unit/AFFS norms. Now, if you are taking the hottest new act at the Red Nights (located right outside the base's main gate) for a midnight ride through the firing range while she rides in your lap . . . and you happen to be distract enough to let your shiny Omni-Mech trip and fall so that a few tons of armor get scraped off with maybe a actuator being tweaked . . . Well, your the mechwarrior now responsible for the cost of repairing your equipment to meet standards (ask how that works to anyone who had to sign papers with Supply after a showdown)- unless your Daddy is also a Lyran general, then the paperwork will say that you were conducting a solo training exercise for the purposes of stimulating distractions such as found in a combat environment. Now the Lyran state covers the cost of the repairs and you get a Purple Heart for the bruised booboo you got when the mech fell.
Inventory, especially during combat operations is what leads me to think there are a lot of impromptu configurations that happen. Your battalion with its 5 or 6 Omnis see a steady stream of action and since its a pair of Black Hawk KUs, Sunder, Firestarter, Templar, and Avatar you use quite a few SSRMs in pods. In fact, one of the Black Hawk KU's was awarded the machine as part of their bravery during Operation Bulldog and as a replacement for the family Exterminator- it was also fitted with Clan weapon pods (R config) which is what the warrior kept on duty. But now combat has been going on for a few weeks and one of the Clan SSRM6 pods was torn apart when the arm was repeatedly hit. So does the tech go back to the mechwarrior, his CO and the battalion commander and say- "Sorry sir, Valencia Vixen, your Black Hawk KU cannot be left in its current configuration since we do not have a spare Clan Streak SRM6 pod or any Clan Streaks to replace it. But we can give you the A configuration which will hit the same range since we have a pair of ERPPCs in pods! Or we can wait 7 hours and hope our veteran tech can repair that Clan Streak system, but sir in that time he will not be patching the armor on a Stalker."
The tech, after getting his ears boxed by the senior tech, will be instructed to pull that frigging pod to be repaired when possible (or scrapped) and replace it with a IS SSRM4 that maybe the Templar is not using. Or maybe they are using 2 SRM4 pods, ton of ammo, and pull the C3 slave since it is deadweight since Jackson's C3M mech was destroyed. If the Black Hawk KU ever showed up at its duty station with a C3 slave in place, or with no masters in the battalion kept it after arriving.