Other suggestions specifically for the game browser?
Actually, yes. In addition to the control buttons on the songlist page, a swipe to go to next subtune would be awesome. I'm thinking in the vein of WinAmp, where I can switch songs effortlessly while I'm driving without taking my eyes off the road. An easily visible yet not too intrusive Loop/Sequence button would probably help a lot of people as well, but it isn't mandatory since it is at least an option in the preferences.
I'm sure you've noticed that whenever M1 is launched it takes ages
to load up even with only a handful of ROMs - would you know why this is? Me personally, I'm using a SanDisk Ultra Class 10 64 GB SD Card formatted in exFAT for proper symlink capability, but FAT32 formatted was slow as well.
One thing that might speed things up for you is if you can make the app use one thread for the UI and another for an extra CPU core. Obviously this will only be something you can enable in preferences on a multi-core CPU equipped phone, but for the likes of the Galaxy S III and Note 2, that could give you significant headroom, especially when changing songs on more CPU intensive system emulations.
What might help your browser is not only larger fonts/row sizes, but also a proper folder
viewing mode, as well as the ability for M1 to automatically check for an "m1" folder on all
SD cards, since phones like the Note 2 and GS3 have an internal "SD" card, usually at /mnt/storage/sdcard0/ and an actual physical slot SD card location at /mnt/storage/extSdCard/. This scanning ability might make initial "installation" on a factory wiped phone (or a new phone) a bit more user friendly. But at least you have
the option to choose manually, unlike with DroidSound, which only sees the internal SD Card storage built into the phone.
As for the stop button fix, that's essentially how M1 works on OS X, so I see no problems with that. When I'm driving, if the swipe feature is put in, I can just quickly swipe back/forth to get the song to start over again like I do in WinAmp, since I can't use buttons while I'm driving.