I have played with the class for a while and I hope you do not mind my feedback.
(Warning; might be a long post)
First of all, thanks for cleaning the class up. The different elemental alchemies are removed. In place 2 new opened trees; gem spells and alchemy potions.
Gem spells; It is an interesting tree, which can activate the special powers of a gem.
*Gem Blast, I expected it to hit several targets like a laser. Instead it hit one enemy, but it is a minor thing I suppose.
*Gem's Radiance; First I thought it would be a escape teleport. But reading it again, it is like an AOE with a special ability from a gem. I would recommend with teleportating further than 1, as only 1 tile is not very useful.
*Flickering Gem; it summons a crystal. Unfortunately you cannot control the crystal, so it would randomly teleport somewhere else. Not very useful I think.
If they could draw aggro.. or if you could direct their attacks, that would be better. Kinda like defensive emplacements.
*One with Gem; the idea is interesting, but it is very expensive when using only one point. You need to invest more points in order to get the special ability of the gem. Right now it is not worth putting 1 point into. Unless the sustain cost is lowered, which brings us to another problem.
*Special abilities of the gem; the issue is that there are not alot of useful abilities. Now I am at tier 4 gems. Most special abilities are only useful when throwing them as a bomb, so when activating them as abilities of gem spells. Others are just no interesting; life gain 5% of max life, lights terrain. Or situational; 50% chance to cleans one magical debuff.
In order for Gem Spells to be more interesting, the special abilities of the gem would need to be reworked.
Alchemy potions; it is a very interesting tree. I suppose this is the utility tree of the alchemist. Different abilities in one tree can be versatile. Having both limtied charges and preperation outside combat, would that be too limiting I wonder? The preperation outside combat, you would need to know what you are facing beforehand. With charges (without the other skills) once you use it up, then you cannot use the potions anymore.
The main issue is the potion themselves. Are they interesting enough that you want to use them? I personally do not think the potions are very powerful. They can be very situational. Yet as the charges are so precious, I cannot see myself using alchemy potions as an offensive tool. And also because they are charges, I would rather hold back on use. Healing potion is always useful. However I would rather use other abilities to heal myself and my golem and use healing potion as a last resort.
*Reproduce; maybe I was doing something wrong, but after the times goes off, the sustain deactivates itself. I thought the deactivation only occurs when you receive damage?
*Potion Sprayer; It could be useful, only if you have useful offensive potions. With limited charges and not very useful potions (even offensive), this would see limited use.
*Ingredient Recycle; the timer did not go down after I threw a bomb. Furthermore to throw a bomb 10, 7 times is too restrictive, because bombs have cooldown. It synergizes well with fast recharge, but even then the amount of bomb you need to throw to recharge one random potion is too much.
Explosive control; I do like how this tree works. It is also very flavorful; your alchemist becomes an artillery. Do the special abilities of the gems come into play?
*Beam mode; If you alot of mana, you can spam beams almost unlimited. It is fun to use. Maybe OP. Maybe.
*Cone Mode; very useful. You throw and then comes out a shaped charged. Like a thrown claymore I suppose.
There are Implosion and Chain blast, which are useful I suppose. I tend to limit myself using explosive control, only in very challenging situations.
Anyway I do like this rework. It is more streamlined. Abilities of Golemancy basic and advanced have become more useful. Abilities were merged and new abilities created. New trees were added, which are interesting; Utility with potions, Artillery with Explosive control and gem spells. This rework has alot of potential. Look forward to see more updates in the future.