Your hack is bad. Check if your files are incorrect or the file size is over it's limit. Possible culprits are info2/info.pac, menu/common/strap/strap.pac and maybe your CSS is bad.
I'm not really much of an animation editor, but you could watch WackaAlpaca's videos. He does tutorials of animation editing that I'm sure could be of some use to you.
I don't believe there's a ROB port over another character, however you can request one to a Character Importer export. Or you can use MR.MW's File Patch 3.5.3 code and swap the folders so you can have 2 hacks over 1.
For better resolution, find a tv capable for high resolution and buy a HDMI for the Wii U (if there's one out there, I'm pretty sure). Also, in some instances, there are actual hacks that have HD content. Search them up in the search bar on BrawlVault.
Exactly what you listed is what's wrong. Those files are there not for just show, but to help the code work. All I can say is, try saving all the images in a folder from your files and slowly work your way up and replace them from ASF1nk's files. Also, for the Stage Expansion, use this:
What CSS mod did you download? Try using the common5.pac file instead of the actual menu2 file. Did you remove the "_en" from the file? Make sure it's named correctly. Also make sure you're using the File Patch Code 3.5.1 so you can replace your codes.