guys, i get how it goes!!! the 1-blah blah is skill gap between what u are making so if u have a lvl 1 skill and ur trying to make something that caps at lvl 7 u have low chances, but by having support it becomes possible for your to do it and more and more +1 etc makes u have a higher chance of synthing whatever u are making, does that sound about right? ,,,,
Right. Basically, all the modifiers get added to your current skill to determine how easy or hard it will be for you to successfully synth at that moment with that crystal on that day with that moon, etc.
If you have a skill of 1 and you try to craft a 7-cap item with no factors going for you, then most likely you'll be failing a lot (and not just failing, but losing most of your ingredients, too). But, according to Purplenv's figures, if you synth on the appropriate day (+1), full moon (+1), with paid support (+2), then that'll put you at an effective skill of 5, so you shouldn't be having many issues successfully synthing (and getting skillups).
So the more support you have, whether it's through the guild, guild items, day of the week, direction you're facing, phase of the moon, or whatever, the easier it is to successfully synth. Of course, if you're trying to skill up, then you want to control what bonuses (or penalties) you want applied so you can keep yourself in the "sweet spot" as long as possible. Too many bonuses and you may put yourself over the cap, and while you still skill up as long as your base skill is under the cap, it'll be pretty slow. :)
As for the original post, thanks for the info. I've started to try to get serious about a craft, and I've been using this to try to help me now that I'm getting into some longer stretches of doing the same synth. I haven't tried to check the figures, but it all looks good from what I've been experiencing so far. (Only 19 crafting levels, but still, it's looking good.) While I haven't waited for certain days or moon phases, I've tried to be aware of what my modifiers should be, and use that to gauge whether it'd be a good idea to get support or try facing a certain direction.