Default Huge issue on android 4.0.4 Tablet..Please help!!

Hey all,
Okay so my best friend is a quadriplegic..He gave me a Digix Tablet model Tab-730,android 4.0.4,base band V1.10_20120929,kernal ver,3.0.8+,4 gb external card and 2 gb internal, to root so I could help him get the most out of his device with accessibility and such..Anyways I successfully rooted it with Bin5ary,and now I have a huge issue I cant fix....

Every time I reboot,it factory resets itself..Every time still showing superSU as an active app..
Then I cant install more than 1 app without it saying its full and to manage my apps..
I read online its a problem with busybox and to copy /system/sbin/busybox to system/bin and reboot..First of ll theres no /system/sbin/busybox to begin with because I cant get busybox in the system...I can make changes with a good file manager downloaded apk from my email,but cant install busybox after..I can install busybox first but then my stock file manager isnt letting me access root!
Please help my buddy and I out! Endless thanks to anyone who can!