Focus on wind imo. Chu is ok, gaia is amazing.
second team should be water to deal with your elemental weakness, which is fire.

Souls that you need Mordred, joan and d'art (only for the snipershot). Those three should be your aim for now.

If you can not do comfortably atleast acc3 than there is no need to push yourself. Soonest on 3 you can find ssr accesorrys. You could always do acc2 for some stuff to sell, get points and buy the ssr rings in the shop once a month.

Weapon grid is the biggest statgain you can have. If you have SR or SSR rarity assault weapons use them. you can use 1-3 defender weapons early on IF they have good base stats.
If you don't have same elemental assault weapons, you can use for the time beeing offelement weapons with high stats. The better your base stats become, the less useful offelement stuff becomes.

Lilim eidelons have a massive flaw in that you need to have 3 different elements in your main team (backrow does not count), meaning that your assault weapons affect only 3/5 himes. If one of them dies and the replacement is not a different element you lose the lilim bonus, the lilim bonus also counts only for one element, and its character attack, meaning its basicly an addition to your assault skill level. The better your weapon grid becomes, the less impactful the lilimbonus gets.

So yeah, don't use lilim as your main eido.