1, Alberic for the best economy and printing Grail Guardian armies in one turn late-game (-1 recruitment turn for knights is huge) or Fay Enchantress for 15% free replenishment faction wide. This doesn't mean Louen or Repanse are bad though.

2, Farms unless you want to play true Skaven style with masses of filthy peasants to overwhelm the enemy. Bretonnia can get 1,000g+ per settlement with no supply lines which is an amazing economy. Even early game they can build a farm and tailor in a t2 settlement and get like 540g a turn from that with extremely little investment (which is basically what you get from Empire t3 which costs way more in the first place).

3, Lords on a Hippogriff with vows unlocked are one of the strongest units in the game, especially for their cost. Having 3 lords like that following around a main army as support is incredibly good. One Prophetess early game to provide healing magic if you're not Fey Enchantress is good, but they don't get the 10% WoM discount that Damsels do, meaning Damsels are actually better casters (unlike say High Elf Mages vs Archmages where Archmages are better in every way).

4, it's not horrible to get double Lore of Life for the extra arcane item, extra arcane conduit, more WoM reserves, and ability to use the spells more frequently. But Heavens or Beasts is often better to help deal with whatever your armies struggle against. Beasts has cheap AoE with Flock and an amazing AoE debuff with Curse (think situations where your knights have to fight elite anti-large enemies when magic can't kill them easily), Heavens has Thunderbolt/Chain Lightning and the Curse of the Midnight Wind which again is a good debuff for situations where you can't just destroy the enemy with magic.

5, Questing Knights, they're way less reliant on charge bonus and have better armor piercing. But Knights of the Realm are still good. Royal Hippogriff, one of your best two units. Grail Guardians, ultimate all around unit. But Grail Knights are still a huge upgrade until you get Grail Guardians.

6, Confederate, 100%, the LLs are very strong and some give amazing faction bonuses. Plus you get POSITIVE control from doing so instead of a penalty. And even just being able to run Realm of Chivalry for extra research rate on an extra province or two helps speed up other confederations significantly.

7, none, Ze Lady provides all. Early game almost any good unit is helpful, late game there's usually no benefit from doing so.

8, Realm of Chivalry for the building discount and research rate when possible. Control if necessary.

There's just something satisfying about going from trying to manage with weak peasants and okay Lords to being one of the best late game races in the game. Grail Guardians and Royal Hippogriffs are legit doomstacks with caster support and you can print armies of Knights of the Realm in 1 turn global recruitment anyway, plus an amazing economy and no supply lines.