First about the jogs:
Make sure you have updated to the latest firmware version which you can find on reloops website.
Follow the upgrade instructions TO THE LETTER!
If your problem persists then you might have altered the jogwheel sensitivity.
There are 2 things in the manual that you should read:
1st reset the TM8 to factory settings (this will delete any bogus jogwheel settings you made).
If the problem persists then 2nd alter the jogwheel sensitivity following the guide in the manual.
If you do not own the manual or you have lost it, then you can download it on the reloop website and actually they have videos on there on how to setup everything.
As for cases:
I use a Magma XXL Backpack. There is a similar case from UDG. They are not specifically made for the TM8 but come with additional velcro buffers that you can adjust to make it work with any controller from TM8 up to DDJ-SX.