It should work just fine as long as you follow the install instructions which I do hope are clear enough. If you have any problems with it, feel free to let me know!
I'm also just gonna note I have a fork of the mod with the changes I made which really isn't much at all, but it'd be helpful to know any bugs, minor changes, major changes, receive help in fixing the sound crash bug or anything else since I'm still learning Java. The fork can be found here: https://github.com/Spyro201/Minecraft-mods
Although I do wanna state, I have no plans to update it past 1.6.4 either since it'd be a lot of work. Although, what CaptainSwag101 was planning would probably be the best way to go for a mod like this, even if it ends up with fewer features.
Hmm... Well that's quite odd. Perhaps try a redownload of it and try following the instructions more carefully, unless you've done both that is. If that doesn't work, perhaps you could share a screenshot of the version tab in the instance window where you install the mod?
Hmmm.... I followed my own instructions with a fresh Multimc install and downloading the zip I gave out and everything worked out fine for me. Perhaps a fresh Multimc install could work? Unless you've also tried that out.