All my lvl 49 purple augments bound and non-bound turned into +18 stat / +12 end. The endurance ones turned into +18 end / +12 power or roughly that, can't remember.
Augment schematics are from running the slicing missions and they are not that common. Pre 1.2 they were for augments, post 1.2 they are for sliced tech parts. The slicing missions cost the same and take the same amount of time to run. The 49-50 missions you get blue Subelectronic Data Modules with crits giving purple Advanced Neural Augmentor and possibly a green 22 augment schematic.
Synthweaving:
lvl 49 green 22 augments take 2 x Upari Crystals, 2 x Primeval Artifact Fragments and 2 x Cortosis Substrate (from crew skill vendor).
lvl 49 blue 22 augments are from RE'ing the green 22 augments and take 4 x Upari Crystals, 4 x Primeval Artifact Fragments, 4 x Cortosis Substrate and 4 x Subelectronic Data Modules.
lvl 49 purple 22 augments are from RE'ing the blue 22 augments and take 4 x Upari Crystals, 4 x Primeval Artifact Fragments, 4 x Cortosis Substrate and 4 x Advanced Neural Augmentor.
On the PTS you can not RE lvl 49 purple 22 augments to learn any schematics, not sure if it's possible or not with lvl 49 blue 22 augments. As for the RE rate, it was rather quick. I RE'd about 5-6 greens to get the blue and about 6-7 of the blue to get the purple. I stopped after that as I got all the info I really needed so take that RE rate with a grain of salt.
Edit:
340 slicing missions in 1.2 do not give augments, only a credit box, a few Subelectronic Data Modules, a few Advanced Neural Augmentor and possibly a schematic.