The illusions, meh. Last time I checked both TSM and the LGM spreadsheet both showed only a couple hundred gold return/unit, if they showed a profit at all (most didn't). They're slow movers as it stands, and there is already substantial competition over that market on my server anyway. So it's not worth the trouble of babysitting/cancelling/relisting for such a nominal return.
I'm aware that the LS chain can be xmuted up all the way up from GIO. This is great since it means ultimately you only need to track/acquire one item. The procs can certainly increase your profit margin, but as I said in my top-level comment the profitability of the whole endeavor is server-dependent. These numbers will of course vary from server to server, and for some it might be worth it.
I think that's server dependant. I make a lot of Golems, but the price on my server is high enough that you could buy all the living steel and still make about 20K (almost 200kg on AH). Its just that you proc all the way up the chain. You proc 20% of your trillium, and then 20% of your living steel. SoH and Ghost Iron are such low effort farms, too. 20% of 180 Trillium Bars at 500g is 18k more profit, 20% of 150 Living Steel at 3500g is another 105kg. That's an extra 25k profit per Golem. If they stop selling stockpile them for the next expansion, they always boom with the price of herbs. And a consistent 20% proc rate is the opposite of RNG, its extra free stuff as a benefit to completing an extra quest (not to mention for new alchemists the investment of leveling Vanilla Alchemy). You're looking for some get rich quick scheme, where the real way to build wealth is patience and volume. No market is going to be viable because you want it to be. Only because you make it viable.