yes to chandler. People used to make candles out of beeswax all the time. I'm well aware that wasps use paper-cement and not wax but still, our "bee" people should know how to make candles (out of other materials of course, not paper cement).
I wouldn't say a separate workshop for processing scales, but I believe wasps should have the ability to process scales. What Meph currently did was add the scales shell and chitin working reaction to the leatherworker's workshop rather than creating a separate workshop for each.
I say no to slaughterhouse because we have plenty of summons already and because wasp's are too short-lived to make use of the potion of strength. If we are going to use it anyway then the resurrect megabeast option should have a chance to be spawned feral like all of our other high-tier summons. Anyway I got a great idea. How about we make it so that a megabeast soul is required to construct the shine to the depths? This will prevent a player from rushing it.
I'm on the fence about the archeologist.
the thing is, meph's default reactions are for full sets only. that's why we made a separate workshop for chitin, because if we put it properly (that is, have the ability to either make full sets or separate pieces), you either need to make a workshop, or the tanner will get drowned with reactions. kobolds have the scale cleaner building, for example.
for the slaughterhouse, what i was thinking was not the options to resurruct megabeasts or for the potion of strength, but adding a set of reaction to dissect megabeasts for resources and a (new and generic, instead of specialized) megabeast soul (which should be used to construct the shrine, because it's a great idea). right now, megabeast corpses are unusable by the wasps.
as for the archeologist... well, it's not necessary, but even the kobolds have it and couldn't think of a reason why wasps should not have access to archeology...