I've advocated for larger mid-late game increases in mitigation to help balance Advent vs TEC as well as research to add Phase Missile Resistance to Cap Ships & the Guardians Shield Projection ability to balance Advent vs Vasari.
PM defense is a good one.
Also, I think the Advent simply need stronger shields. The mitigation upgrades come only when they're researched and when you're lucky enough to be fighting in friendly culture. I think either the Advent need stronger base shields (by 1/4th or so: like 1000 -> 1250 for all ships), or higher shield research benefits (instead of +5% -> +10% for the first level, something like +8% -> +16% and so on). Or both.
2- Economic Disadvantage- This one is a bit more difficult, I have had some thoughts of a radical change that could be made or a series of subtle changes. My Radical change idea is to make Resource Focus simply an unlocked passive ability that is added to the Advent Trade Port so you continue to receive trade income while at the same time receiving the benefits of resource focus. I would balance this by making the original research and the subsequent increases to Resource Focus more expensive. I believe this 1 single change could go a LONG way toward improving Advent economy.
Alternatively- a series of overall cost reductions to research and trade ports along with moving Allure from tier 8 down to I think Tier 7 or even 6 would also help substantially with Advent's Economic woes. Perhaps allow 2 Tiers of Allure, the 1st 2 upgrades at Tier 6 and 2 more upgrades at Tier 8. I might find 2 extra lab slots to raise overall Max Allegiance on every planet to +20%.
The Resource Focus buff would be a plus, but increasing its costs wouldn't be a good idea IMO. Structure resource economy is rarely if ever used anyway, in competitive games. If anything, I'd like to see your passive Resource Focus idea, combined with a reduction in cost (in needed civic labs, maybe).
If Resource Focus were made to be a viable thing to research, even in competitive games, that would be quite nice for Advent.
3-Next: the Illum..... I know of a simple solution, I am not certain it is easy to program but essentially the Illum problem lies in the fact that it cannot focus fire as its beams spread its high potential damage across 3 targets. Very effective against massed soft targets, not so much against a few hard targets.
Illum DPS is 17 which is the highest of all the LRM's. However, divide that by 3 and you get 5.67 per target. This means that when focusing fire, it takes 2 Illums to equal 1 Javelis and almost 3 to equal 1 Kanrak.
Not exactly. The front beam does 50% of total Illum DPS: the side beams each do 25%. Against a large target like a starbase, or 1v1 with another faction's LRF, Illuminators will be in trouble, but they are capable of some focus fire - just not enough to be all that effective.
Still not as high as the 11 Javelis or 14 Kanrak, but much more respectable in fulfilling the needs of a LRM.
I think it generally makes good sense to calculate DPS in terms of DPS per supply rather than DPS per frigate.
Of course, Advent's is still significantly lower against single targets, and significantly higher against multiple targets (except if the enemy is Vasari with upgraded Assailants and is targeting your caps/SB, in which their DPS is even greater I think).
I'm all right with the Illuminator being as it is, combat-wise. The underlying problem is the Advent's vulnerability to early-game enemy Orkuluses. Carpetbomb had a thread on this a while back. While that is an issue which should be somehow addressed I don't think that Illuminators are the problem that needs fixing.
4- Channeling: To me Channeling is not really the key problem with Subjugator abilities IMO. I believe the must face target requirement and range are more of the issues. If you could eliminate the requirement to face the target and extend the range to somewhere in the 8,000-10,000 area, I think the subjugator could be a respectable little healing ship. It's main purpose would be sitting around and healing things inside of the battle-ball. The reason I say extend the range is this helps to balance channeling as your ship will constantly be stopping and starting to channel which really kills the move speed.
While that sounds interesting and would certainly make the Subjugator significantly more viable, I think quick and effective fleet-wide hull repair is a TEC thing with Hoshikos, and is not something that other factions' (offensive) fleets should have. Then again, it's more important for Advent to become more balanced again, and for the Subjugator to be usable for its research cost.