Well, are the team textures going to be required in the PMBR recommended tournament ruleset, or just optional? (Or did you decide not to make a recommended ruleset?) If required, include them automatically; if not, then add them to the "extras" folder.
Melee music should also come in the "extras" folder, along with a very direct text guide on how to add them (create this folder on your SD card, rename the file xxx to replace this song or yyy to replace this song, etc.). The only reason that I don't want them included by default is because even things like Yoshi's Story replacing Yoshi's Island Melee have 2 song choices on the stage, and the user should have the choice to decide which of the 2 songs to replace with the Melee song. It's a minor thing, yes, but it adds to the "not being forced" idea. A lot of people don't know how to do any modding stuff so anything that's included by default is basically considered a permanent fixture to them.
The extras folder should be included with the main download, in a location that doesn't interfere with the game play files. Hopefully on the website you would create a section explaining the extras, saying that they are NOT required to run the game, but are optional simply to aesthetically enhance the experience.
You may or may not also consider adding the a few of the Melee character vertexes to the extras folder. Only if the quality is up to your standards (like the Melee Fox with the imported head IMO).
