vlc likely will not play the main feature.
Out of curiosity, what makes you say that? VLC should have absolutely no problem playing a high bitrate x264 file in an m2ts container, in general. If it’s a matter of the hardware not being good enough, I’m not sure that other software will solve the problem, but perhaps it will!
MusicallyInspired: Did you play the mounted ISO as a disc in VLC? And it actually showed the menus and everything? Usually that is the more difficult part for VLC to handle. But the main feature itself should work. If you browse the mounted ISO on whatever drive you have it on (F:\ for instance), you should be able to see the folders: BDMV/Stream/. Browse there and click on a few of the larger m2ts files and open in VLC. They should play. The one that is by far the largest (many GB) will be the movie itself. Does it play that way?
Edit: Having just seen the updated post, perhaps it is just a matter of the computer not being capable? The main feature is much higher quality in terms of bits per second your computer needs to be able to run, compared to any bonus features.