The photonics make sense as a utility tool, since it allows us to use simple tools that regular soldiers might need without having to think of carrying everything. Its a nice anti-frustration feature for those of us who cannot be meticulous over a text format.
My biggest concern with using them for weapons is the simple fact the only reason I know of this is because Wes said so. I have only his word and for all I know tomorrow that might be rescinded, or someone might invoke a higher canonical law. Nothing on the wiki defines their use or killing ability. Even if I have an okay idea of that, without anything concrete to refer to it would be all too easy for me to declare an action that would be outside that and cause an extended argument. I also don't know how elaborate these weapons can be, or if any limitations to their shape are in order.
So yeah, with so many questions I can't consider them something I really want to make extensive use of because I'll likely shove my foot down my throat. The solid volumetrics page is more technical fluff than anything, which doesn't help any.