Optically speaking, I believe that the current VX-1 is the same as the later/improved 2005-2011 vintage VX-II.

I have several Leupold 3-9x40s, from pre-1974 Vari-X to VX-1. My VX-1 3-9x40 is the shotgun version with a heavy duplex. It is on a Savage 220 20 gauge slug gun that I use to hunt deer in Iowa.

To answer your three questions:

1. They're OK
2. No
3. Not with the heavy duplex