Correct. If you use the headshell supplied with the tonearm, it would not be possible to twist the cartridge with respect to the long axis of the headshell, unless you somehow modify the headshell. However, the tonearm accepts all standard headshells, so it might be possible to use a conventional headshell and twist the cartridge at an angle so as to effect a "conventional" geometry, with the stylus overhanging the spindle. Also, there exist a very few headshells that incorporate the offset angle into the headshell mount, meant for mounting on a straight pipe arm wand. I think Garrard made a tonearm like that. Such a headshell could also be used.
As to your first question, no, I have not removed the O-ring dampers from the arm wand.