No, guilds began to devalue when we gained guild perks and levels, and it became a thing to shift to larger guilds of pure numbers in order to level the guild faster and unlock more benefits, LFD did no such thing, all it did was quiet down the LFG spam, LFR did no such thing either, cata is a bad metric for it since it was only one teir, look at MoP and we saw more people trying to raid, and plenty of them came up from LFR.
You try to equate LFR with cata’s failing, while pretending the real problems from it didn’t exist (for example, the Heroic Dungeon difficulty, after spending all of wrath giving people easy peasy AOE fest heroics, they tried to up the difficulty in cata, while it wasn’t bad, the fact it slowed groups down and led to more wipes with harder hitting trash. caused outrage that led to a overnerfing)
Your stance that 5 mans are more popular has more to do with the spammable nature of Mythic+ as well, you do realize many raiders hit them up to spin the loot wheel in a effort to get extra gear to help raid more, by taking away raiding and pushing people soley to Mythic+, your going to see their popularity drop as well (i know plenty of people in my raid group and others i talk to who only will run 1 a week for the chest, without raids, they wont run any) not to mention we already see issue with them as people get pissy and drop group all the time wasting a key, or not wanting to do them at all because they feel the requirements are too high.
The only thing i could agree with you about is they need to rework class design, something they have said they understand now as well (as to if it will happen… im not holding my breath), most of your ideas would frankly push more players out of the game, by catering to a small minority, something WoW has tried before, with poor results (warlords LFR anyone? Pathfinder?)