Regarding the video issue, I don't think you understand what he's trying to say. There are tons of cards out there that support OpenGL, but only a handful of them are going to work with LMCE. Also, it's actually not LMCE's problem either, it's more of a Linux in general issue. You see, the video drivers that are available for linux determines how well it's going to work with Linux. And the only company out there putting forth any effort in stable, reliable, effecient linux drivers is NVidia. Hence why everyone recommends going with Nvidia cards.
Concerning the permissions of your share, did you click "not use" and "make all public" or the other?
I would recommend deleting the device from the webadmin page and allow it to re-detect and reconfigure the share.
Try setting the permissions manually.
chown -R linuxmce:public /mnt/device/33