I raised this question with Rob Boyle last year, and his response was that both rules do apply.

Errr... I guess it's balanced out by the fact that you're forever restricted to reach 0 with it, but it just seems odd that two sets of handrazors (sharpened metal fingernails) would so heavily outclass someone with a pair of knives.

I'm almost tempted to work up a physad with dikoted cyber spurs and see how it works out. Making foci out of them is also problematic.

The Zeiss eyes appeared in the German version of the German sourcebook, along with other equipment, gear, vehicles and contacts. Hardly any of the items found their way into the english books. So the UV-feature is according to my knowledge a german feature for the Zeiss eyes.

As some have pointed out, the Zeiss-Systems are currently german-only (from a certain POV I'd like to say: Hopefully it stays that way).
There are no rules on how the UV-System works in terms of game benefits (like the vision modifiers for IR-Sight or Low-Light). The creators didn't put too much thought into these systems in the first place (there weren't any rules in the previous SR Editions either) and now they have been transfered to the german M&M without further inspection, which usually leads to a whole bunch of questions. The one about the UV-Sights being the most common one.

As for possible game effects of the UV-System: There aren't any in terms of vision modifiers: Only a very small number of materials reflect UV-light. Most of the UV-light is directly absorbed :arrow: there's not much of an illuminating effect coming from UV-light. You can see that in discos where they use UV-lamps: Some clothes (especially those which were recently washed with some sort of bleech), have a glow but that glow doesn't illuminate it's surroundings too much. Same for materials that show those fancy blue / red / green glow effects.
Under normal or even reduced sunlight these glow effects are next to invisible.
So the main use of these effects is commonly in trying to mark certain objects (like bank notes, that can be identifed as being authentical).

No you can't. As to why: Because the rules don't say so. That's special trait that has only been defined for cyberspurs and handrazors *note: not cybernetic handblades*. You could transfer the effect to the snap-blades as well.
For Killing hands, the main problem is, that you'd have to transfer it to normal melee as well, since Killing Hands works on unarmed combat. Thus removing the specialty of doubled spurs.
And of course there still is the dispute about that 150% bonus for spurs once you play with the advanced melee ruleset.

As I said: There are no such rules .. Not in M&M nor in previous Editions. The only thing that comes close is a Shadowtalk remark (yeah, we did get Shadowtalk in M&M) where it says that someone using the UV-Vison failed to notice an UV-based photo-electric barrier due to the UV absorbing effects of standard glas.

Again, no specific rules on theses systems at all.
These systems incorporate several subsystems that you'd have to buy as seperate modifications to standard cybereyes at in comparison overall lower Essence cost but also higher monitary cost. Depending on systemtype you also get a number of slots that can pack certain pre-constructed packages (IR, low-light, camera etc.) with specified essence costs. Zeiss-Systems can only incorporate those Zeiss-packages and vice versa...
And that's also the next place where trouble arises, since due to the lack of explicit rules the usual question is: Do you also get the 0.5 Essence in other modifications for free or not?
The next problem is that there are certain options that are not availibe for standard eyes at all.
Nor is there a statement about higher cyberware grades for those things.
Certain combinations of the Zeiss-Systems in their basic configuration do provide the same benefits standard eyes can only deliver at betagrade. And that betaware would be more expensive in terms of money and about the same in essence cost and has of course much higher avail ratings than those of the Zeiss-Systems ...