Well since everyone is sharing...
The tactic I'm using is to evaluate the synths is like this:
Subcomponents (the 40 durability items):
- Most important question: Can I fully complete the synth in 1 shot?
The simple answer: Yes. At level 50 I can oneshot most synths level 30 and below (My current return is 115 for progress right now for non-starred synths). At level 36 I can oneshot synths with a progress of less then ~56 (if memory serves me correctly). It is actually faster and more reliable to do this, than it is to use the Quick Synth option. The only benefit to quick synth is that it is an unattended option, where oneshotting requires constant interaction by you.
- How much CP do I have to set aside in order to fully complete the synth in 1 shot, if possible?
None, you don't need any CP to oneshot a synth. I use Careful Synth 2 now, but Basic Synth can generate enough progress to complete many synths (especially level 1 synths), and if you use HQ ingredients you have better than the 1% chance of HQ that the Quick Synth offers
- How much quality can I get with what's remaining without having to refill durability?
Not really sure how to answer this question. If you are asking how much quality can you get without using one of the Durability return abilities, based on standard CP, I would expect, with normal abilities without regaining any CP, I would guess ~500. Waste Not, and Manipulation allow me to triple that amount, and Tricks of the trade allow me to maintain my CP for the most part, so, tripling that value is possible, and fairly easy with those abilities.
- Am I willing to take the risk of trying a non-100% chance at a Good, or should I just Trick the Good into another 20 CP for now?
I ALWAYS use tricks of the trade on a Good (unless I am in the finishing stages of a synth). The Quality return is not worth the CP loss. (IMHO)
Final products, on the other hand, are far easier. The goal on them is to get as high of a quality as possible. Unless I am trying something 4+ levels above me, I know I can use the synthesis abilities to "pass" time as I'm waiting for a Good or Excellent, since I have to use them at some point anyway. This is the area where Rapid Synthesis is palatable and where I've been considering using it, although if it takes longer for Rapid to complete anyway due to streaks, I'd probably still say "forget it" and stick with Careful Synthesis II or Standard Synthesis.
Personally, I put building inner quiet above all else. A high inner quiet can mean a 1k+ gain in a single action (only takes 4-5 successful quality actions) when used with Great Strides and Innovation and Advanced Touch (Standard Touch, you can get a 500-800 quality gain). Done well, you can get two of these last minute pushes for 2k+ quality in only two actions. That can give you HQ results from NQ results.
Mind you, you need excellent gear for your level, good timing, and ~160 CP near the end of your synth to pull that off (for Advanced Touch, you would only need 128 for Standard).