which out of these profs would be best to round out my chars

[Rogabr]

I currently have 3 90's.

Jc / chanting
Mining / tailor
Inscription / ???

Looking for a 6th prof to round out my chars for making the most money. Looking into either alch (transmute) blacksmithy or engineering.

also not sure what to do if I pick alchy. Would I turn uncommon gems into rings necks and de it then make chants or would I take uncommon gems get golden lotus and turn em into blues then cut and sell those. Or would I do both and cover the markets?

[GhostSkull]

The Tmeless Island giveaway and PVP screwup have gutted the armor market. The mount market is a bit saturated. I'd pick whatever you spend the most on for your own use. Think of saving gold rather than making it.

[Ihnasir]

Engineering could bring in the most gold through mounts, especially the Sky Golem. Blacksmithing may bring a bit after crafting the daily cd pants or belts. I've noticed that through JC, rings/necks don't sell well anymore because of the Timeless Isle and access to higher LFR difficulties because of ilvl inflation. Tramsute alch may bring in a bit, but Living Steel only goes for about 400-500g a pop on my server. If you stack up a lot, sure, it could give you something. Jewelcrafting is still hauling in a fair amount due to alts and people getting more gear from SoO, so Alch might work out in your favor there as long as you have the cuts people want. It's a complete toss-up to me considering the randomness of what patterns you get through daily cds, but I feel like Alch or Eng would be your best bet, leaning on Alch.