Steady Hand, and later, Steady Hand 2 (from Culinarian at level 37). Add 20% (30% with SH2) to that 50% bringing it to 70 (or 80) percent chance of working. It is 2.5 times as strong as a Basic Synthesis, just a hair over twice as strong as a Careful Synthesis 2. And, it costs no CP to use. It's really a skill for when you have a lot of Progress left to make, though there are other, better, options available at high levels.
And
Sort of. I don't recall the previous mechanics, nor how exactly they got changed, but suffice it to say that the move (and its upgrade, Ingenuity 2, at level 50) make the harder recipes easier. The effect is that the level-based penalty is lessened. Recipes higher level than your own have a level-based penalty. Heavensward recipes have a worse penalty than Realm Reborn recipes, by the way. This penalty reduces the amount of Progress and Quality you can add with any given move. Ingenuity and Ingenuity 2 serve to reduce the recipe level somewhat, which then reduces the penalty. Now, if the penalty is not there anymore, these moves have no effect (you get no benefit from it for being a level blacksmith trying to make bronze ingots). Also, if the level differential is too great, these moves will not have any apparent effect either - this was observed prior to Heavensward, with the 3 and 4 starred level 50 recipes.15 Ingenuity - Lowers recipe level to current level for the next 5 steps. (24 CP cost). This one I think it's saying if you're level 30 trying to do a level 34 recipe does that mean the recipe now becomes a level 30?
Then:
I found this to be a worthless skill. Inner Quiet is a skill you want to hit first off, pretty much always. It increases your Control by 20% each time a Touch is successful. This has the effect of increasing the Quality added by the next touch by around 10% of the base, starting Touch. If your first Basic Touch was 30 points, your second will be about 33, then about 36, 39, 42, 45, and so on. That is much better than simply adding 30 Quality per Basic Touch!15 Rumination - Removes Inner Quiet effect and restores CP proportional to the number of times control was increased. - I have only used inner quiet a hand full of times, mostly because i just don't have the CP to maintain it and everything else, but is the CP restored worth using this?
Rumination, however, I found worthless, as I said. There are two reasons for this. First, it teaches a bad habit. Using the skill suggests adding Quality first, then using Rumination to get the CP needed to push the Progress through. This is backward compared to what you are going to be doing once you get Byregot's Blessing. Byregot's Blessing is a move that also kills your Inner Quiet stack - but it adds a TON of Quality when it does so, based both upon the fact that Inner Quiet raises your Control (for more Quality) and that BB gets a bonus to the Quality with each IQ stack! Once you get Byregot's Blessing, you will be focusing on Progress first, until you are one Careful Synthesis (1 or 2) from finishing the synth, then building your Inner Quiet stack as high as possible before using Byregot's to maximize your Quality. The other reason I never found Rumination useful is I never saw it add enough CP to Waste Not, much less any other Durability-affecting move. No Durability increase meant that whether I used Rumination or not, I was about to finish the synth when I was done with my CP anyway.
The other 50% chance move is Hasty Touch. This move costs 0 CP, enabling you to use your CP for Steady Hand 1/2, and for "Durability games" - effects that reduce Durability losses or that restore spent Durability.The rest of them i can see a use for, those kind of seem useless, but that may be my lack of crafting experience lol. But that 50% one is just something I don't think I can even attempt to rely on. RNGesus does not like me. If I use a touch ability it's gotta be with the one that increases success rate by 20% other wise it's all fails, 80% success sounds like a lot, but it's already a 50/50 chance to succeed (And I have recorded this, 348 touches used 163 fails, a little under 50% but still nowhere near 80% chance to succeed.) And it's things like that don't make crafting very enjoyable for me. But again maybe I'm doing it wrong.