With Alina's Sucking Fat, I do see the bite animation. But it takes a little bit before that starts when I use it for the first time in a battle. She will move up, the game stops for a bit as if calculating or loading (during this time, Alina is still bouncing so it's not frozen), then the bite will happen and she starts "drinking". Any use after the first in a given battle will not have that delay between moving up and the bite.
This happens on both Some and All battle animations for me, and the Eating animation setting doesn't affect it. The only time it doesn't delay is when I have battle animations set to "None".
Regarding difficulty, I was thinking just increase the Tournament Point rewards at higher levels. Still not locking anything behind difficulty that way, yet players succeeding at the challenge can unlock things faster.
Alina getting a nerf isn't a huge surprise to me. Although it's probably because I am using her ability to deny BP from her targets that makes said sweeping so easy. The first fight is often the toughest for that reason.
Is the game maybe on a hard drive, not an SSD? Because this one animation is something special and I don't think it's preloaded. I probably don't notice it because my hard drive is a bit faster than a normal HDD or SSD. But I will see what can be done to load this animation at the beginning of the fight when Alina is involved in the fight. Then the delay should no longer be present on slower systems or slower storage media.
Since you can change the difficulty at any time and the points are not calculated per round but at the end of a week, this would only be exploited. Play the first three fights on easy and then defeat the boss on hard to get more points for example. As I said, the level of difficulty is only there to challenge yourself.
Just like the other reply's, it can be your hard drive, but it may be others. I could try to pinpoint the root cause by answering these questions:
What OS are you using?
Do you have a HDD or a SSD?
How fast is your processor?
Is your OS and/or processor x86 or x64?
How much RAM do you have?
With info you give me to answer the questions above, I will (probably) be able to help you out with your problems. After all, I LIVE for computer hardware maintenance and repair.