Regarding resolution:
Quake renders at 320x200 and scales up to 480x272. Unfortunately this is much lower quality than rendering full size. Unless you like the fuzziness, which I kinda do.
There are many places in Quake levels where it performs badly even at 320x200. At 480x272 it would be unplayable, so adding the ability to up the resolution isn't high priority.
When hardware acceleration comes along, it should be a non-issue anyway.
Regarding the crash:
I couldn't find an error message like that in the Quake code, are you sure that's what it says? Also, does the bug show up in the PC version?
Regarding the picture:
Aww, the poor shambler! :) Does anybody else prefer the old picture?
Feel free to send me your favourite screenshots - if I receive any, one of them will be used in the next release.
In the mean time, it is possible to replace the picture by using a tool like PBP unpacker ( http://www.pdc.me.uk/pbp/ ).