New TSHv3 commands are described on this page, with SW_VIEW at the bottom. As you have read, all of these commands (with the exception of the CMDS_MODE command) are found in the "Filter Graphics" section of the custom keymapper.

It is normal for TEXTURE_TRANSITION to not appear on the list when TSHv3 is installed; this command was removed in TSHv3. If you want to change the texture transition setting, you can do so in the game options, but not in-flight. SW_VIEW, however, should be there. You say the "Filter Graphics" option are "the one with the eye", but that's not true - "Filter Graphics" is the cube icon. Try there. \:\)

You don't need TSHv1 wideview applied, although if it's already applied and you've installed TSHv3, don't mess with it. The TSHv1 installer on your desktop is only a shortcut and can be removed at any time.