Personally, I think crit trumps all when it comes to crafting skills.
P.S. Great Post
I fully agree.
The importance of crafting your own items, versus just picking them up via commendations/rewards, is the critical version.
Given this, I value the amount of a critical manufacturing bonus twice that of any efficiency bonus. After all, I can always wait a bit longer to finish a task. I can't, however, improve my probablility of scoring a critical result on a crafting attempt, except through my companion's inherent critical bonus.
Also, the value of the Sith Warrior's companion bonii comes in conjunction with other characters. For those running alts, e.g., the Sith Warrior serves as an excellent materials collector for a Sith Inquisitor Artificer, and in return, the Inquisitor perfectly backs up the Synthweaving skill on a Warrior.
And yes, superb post. Great work here!