https://github.com/jindrapetrik/jpexs-decompiler is a flash decompiler and ide. Edit flash source & view assets, etc.
https://github.com/ruffle-rs/ruffle is a emulator for flash written in rust. It doesn’t support all of the API yet. If you look at the FAQ there’s a link to a webarchive’s archive of adobe’s flash debugger tools. It’s in google drive.
Swiftchan is an archive of .swf files (mainly flash games).