Mostly on the same page except for this. There is no logical reason why 32% is arbitrarily better than 35%. DR for crit from crit rating and from strength are completely separate.
Maybe at some point you were a little high on crit rating which is why you saw benefits in dropping it for power, but it makes no sense to me to say that 32% is just flat better than 35%. In any case I doubt you'd see noticeable differences in upgrading just a mod or two, especially on a spec as proc-based and streaky as vigi.
you will - try it for your self get 35% crit use the rotation Plasma Brand - Strike - Sunder - Overhead strike - Blade Storm - Sunder test for 6 min 3x you will find you dps output is within 30 dps each test if you do it correctly (not using masterstrike avoids the influence of proc chance). Then lower you crit to 32% and test 3 times for 6 min same simple rotatoin. you DPS will go up.
if you spec Inisght only 1 point instead prefering Momentum you will find 34% is best.
As you say this is to do with the value you get from specific skills critting vs the blanket value of damage increase from power. Its the same with Sentinals - all the best ones spec 30% crit not 35%. crit and power are not equivalent in all regards except for the diminishing returns of crit as you claim - although im sure this is by far the biggest factor. you do say this your self in your post regarding force sweep so im not sure what else to say.