Im not entirely sure on the games/mods aspect but I do know very well you should not use your Motorola charger,
The voltage is right but the Ma is incorrect causing an unstable charge when charging,the MP4 player can catch on fire because it super heats the battery.
And also do not get this charger shown below:
It's not built right and have had 3 of them which have all burned out,along with my last Rockchip Touch MP4 that caught on fire because of it.
I would recommend getting a $10 charger from RadioShack because as you charge these on a PC the screen on the MP4 stays on.
I hope this helps.
BTW one of the reasons you MP4 doesn't really have any games or anything is because it's newer.