SFJake: I believe its U to toggle mouse aim on or off.
I don't know how its all setup in the GOG version, but you need to go through the setup.exe (from within DosBox) to get to the control menus and such.
You can also just open up SW.CFG in a text editor and change things in there, carefully.
I've modified the SW.cfg file using Notepad, changing the controls to something more modern-feeling.
WASD- Forward, Backward, Strafe-Left, Strafe-Right
LCtrl- Crouch
Space- Jump
Open- Problem
By default, Space is the open key. Before I tinkered with the SW.cfg file, pressing Space caused Wang to Fire. When I changed it to E, it caused Wang to Fire and Open. When I changed it to both E and R, E caused Wang to Fire and Open while R just caused Wang to Open. I removed the E and left the R, however now pressing R causes Wang to Fire and Open.
The simple solution is changing my bindings back to E and R, then using R to Open while keeping my finger away from the E. This is something that still bugs me, as I can't simply bind the key without a problem.
Is there any way around this, to just bind the one key, preferably E, and have Wang simply Open when it's pressed? To be clear, I've made sure that no keys are double-bound, so that isn't an issue. And, just to be clear and add emphasis, the fire-and-open issue existed with the default bindings.