I think you wrapped my response up into the no AP. I think they should have AP, but should not ignore Firewalls.
Offensive Oblivion doesn't stop an ARO piece, or any piece you want to walk past. I've used Carbonite from time to time, though I agree that Oblivion is more often the right choice. Oblivion followed by Carbonite is also very relevant. Used it last night to stop a Hsien from reaching a scoring zone in Frontline. Oblivion wouldn't have been enough since he was <8" from the zone already. And the numbers are close to the same up to BTS 6. It's only against BTS 9 that Oblivion starts to pull far enough ahead to matter in terms of reliability.
This is a band aid fix to a greater issue plaguing the game. I'm still of the opinion that the entire N4 hacking system needs to be overhauled. CB did far more damage than good with the N4 changes to the system and they utterly failed in making it more streamlined. I challenge you to go through army and count the number of non standard hackers packing weird combinations of shit like hackers with no device just programs, random ECM, or the ever increasing variety of profiles with unique programs. It's just as much of a mess as it was before and it's only going to slide further in that direction with every new faction update. Burn it to the ground. Start again. The Fireteam overhaul was big series of changes and it was an overall positive one in my opinion. Give Hacking the same treatment.
yes, I did sorry, and I agree either give KHD's baseline (and change mary's upgrade) or as the -3 to wip should stay, have repeaters grant ECM: Hacking (- 3). Though on Mary, she is one of the few KHD platforms in I have found remotely reliable for being used as intended, though any with DAM +1 can threaten the mid tier well enough. Thats normally what the missile, white noise or smoke is for, and often much more reliable.