[Weaseal]

I don't know what that SETENV bit you have is... What is 'disappearing'? Is that your group or your user? For groups, you must prepend it with a %;

 %wheel        ALL=(ALL)       ALL

For individual users,

weaseal    ALL=(ALL) ALL

As to your xorg driver, you will need to know which is most appropriate for your card. If you want to see what driver it is using now, edit xorg.conf and look for 'Section "Device"'. Here's mine:

Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz"
        ### [arg]: arg optional
        #Option     "NoAccel"                   # [<bool>]
        #Option     "SWcursor"                  # [<bool>]
        #Option     "UsePIO"                    # [<bool>]
        #Option     "ShowCache"                 # [<bool>]
        #Option     "VideoKey"                  # <i>
        #Option     "NoSLI"                     # [<bool>]
        #Option     "TexturedVideo"             # [<bool>]
        #Option     "DRI"                       # [<bool>]
        Identifier  "Card0"
        Driver      "tdfx"
        VendorName  "3Dfx Interactive, Inc."
        BoardName   "Voodoo 3"
        BusID       "PCI:0:5:0"
EndSection

The part that says Driver "tdfx" is the relevant information. You *may* be able to detect automatically the proper driver via

X -configure

but if you need an outside driver like ATI's catalyst or nvidia's 3d driver, you will have to install them via ports.