OK, I think I got a halfway decent roadmap. It takes a while, but not nearly as long as BlazBlue Continuum Shift's Abyss and doesn't require you to get to Level 99.
But anyway, here I go.
Character of choice: Ken Amada
Skill tree:
1. Weary Thrust. I used this until the very end when I needed Dekaja to stop her healing. I fully intend to put this back before I do Ultimate. This is a big time lifesaver and turns full bar fights sometimes into 2 hit fights.
2. Treasure Radar: Absolutely essential. Make sure you grind this one immediately. It makes your life going on twenty times easier.
3. Beat the game as normal.
4. The skills I used to (Treasure Radar gets removed last)
a. Divine Grace: EX healing a lifesaver
b. Die For Me!: Trust me, if you get lucky, this saves time. Absolutely essential.
c. Full Analyze: Risky Floor 165: You need this. This shuts off her projectile ability, God's Judgement, and her gradual healing. Don't leave home without it, and also good for making all the other fights a heck of a lot easier.
4. Dekaja: The last of the skills you want to obtain, this prevents her from awakening and using her healing Super which restores 75% of her life. You will get rid of this after you pick up Fury of Yasogami if you're going for Ultimate, since once you get that you won't see her ever again.
As for stats:
I focused on strength, endurance, and agility. I was like 130 Attack, 144 Endurance, and 155 Agility when I beat her. Being as fast as her helped a ton. I was also Lv. 83 when I slammed her into the ground.
As for Ladder strategies:
I used a mixture of auto-combos and Ken's D + F + Hard Attack move, creating a trap and keeping it in. Beware of super meter and wake-up supers using this: Yukari on Floor 130 is especially a pain and will counter you: You have to be patient there.
Tetrakarn is a pain. If you notice it only use the first few hits of the auto-combo to slam into an enemy: You don't want to stupidly kill yourself.
Bad matchups: Labrys and Shadow Labrys are the worst: They hit hard, and they love to spam their axe swing take hits super. Minazuki (both forms) are also a major pain, they tend to get around your traps and are good for rushing you down. Be careful with these.
First time I got to her I was Level 66. Being 24 levels under her is a really bad idea. I had to redo the Ladder a 2nd time to get experience. She was much more fair after that.
Number of attempts on Golden Elizabeth: 20-ish. Not terrible, I've seen worse (:: cough :: Shin Akuma in SFxT took over 70 :: cough ::)
She also helped me out by using her sacrifice super taking half of her life off. Thank you for being generous!
Enjoy.