Probably a tall order, but if you can do 160 exp and 80 ult in a single day, that's 15 mil union PP. It's actually doable with just grails and no paratrain assuming someone in your union has at least mid 40k power-ish. If such a person doesn't exist or is not motivated, then cut your losses and try to hit 300 ult - there is actually one SSR axe there. The 30 ult should also translate to almost 1 mil PP, so hopefully you can grab the last lilim which is at 15 mil PP (for stats stick or orb her if you don't need her.)
Good luck finding a better union for the next UE.
1. When all 5 accessory slots on a hime is unlocked and is equipped with at least 3 tiaras, you get a set bonus of +15% DA and TA that stacks with other sources of DATA (basically the hime gets the equivalent of 3 Rush++ weapons and 5 Barrage++ weapons at slvl 20 - good luck trying to replicate that with weapons, hence why tiaras are so sought after)
2. MGRR speeds up how quickly the rage bar depletes from dmg (e.g. if you have a total of 10% MGRR on a hime, and her dmg depletes the rage bar by 1% normally, it will deplete it at 1.1% instead.) It is generally considered useless and should be a high priority for selling/foddering.
The best accessories are ones with useful effects, and those are completely random, so no tier list unfortunately. If you are interested in what other set effects there are besides tiara, check the link that AutoCrimson provided you. Earrings are sometimes used by people, its set effect is 30 BG at start of combat - useful for quick FB outside of BT.