Problematic MD3 import

I extracted this 3d model for modding purposes and I immediately start to notice some glaring problems that I can’t find the solutions for.!AmL2O3ielaAbhDFEZXnS-V_GKvLQ?e=0gDf6N

The problems:

1, The timeline and key-framing in this is a mess and I’m have no idea how I can organize this better.

2, Due to the way the 3d model was extracted, what were suppose to be different poses/shape keys are merged together as two seperate meshes (like the conjoining of his hands closed and opened, and the blade staff conjoined with the skull staff). In order to clean this, I would have to delete one of the two in all frames and then attempt the same with the other. How would I do this?

3, If there are distortions due to extraction, such as ugly deformations or missing accessories, how can I add them on the time line on specific frames?

Thank you