Although I do agree with the State Alchemist that this ability is amazing to have for this kind of situation, it should be noted that, at least in my experience, Hand of the Gods is very fickle about being available for me in a synth. Many times I've been put in State's position on another synth, with anything under 10 durability left. Whilst doing a combination of "Wait" and procing other abilities, Hand of the Gods never appeared, leaving me to do a Standard Synth with only 2 durability left and hope for the best. This may just be my horrible luck, but just a warning: Don't always rely on it in the end!
I actually often use mine at the beginning of a synth when trying to HQ something. Since synths are often easier at the beginning, you can get a few Bold Synths in with no durability loss and essentially be "starting" the synth with 20-30% progress.
As for the Touch Up idea, if I remember correctly, I had this happen to me once and it ended up not working that way. I still lost durability during a Touch Up. However, it was one time and I don't even remember completely, so it's definitely worth testing!
Edited, Mar 2nd 2011 6:51pm by ArkWeldwin