I haven't checked the DVI port on the back of the 3500 yet, and I did a search to see if this topic had been raised before but I couldn't find one.

Can the Voodoo 3500 function normally (as both SVGA and TV Tuner card) without the 3dfx S-video cable junction box thingy?

I have never bothered to try it when I had the hardware out, but now I am interested if it will actually work or not?

Can I plug the card in and run a DVI monitor directly off of the DVI port on the back of the 3500?

I never checked.  When I bought mine (quite a while back now) I got a brief glimspe at the port in which the 3dfx s-video cable box attaches.

I thought it was a DVI.  I can't remember what I saw.  I just cannot be bothered to go and get all the equipment out.  Ah well, sorted it anyway.