If anything I would tell you that you have too much defence and not enough shield/absorb.
The truth is that both those set ups will work, this game simply does not require you to have the best possible stats available. Healers will, however, have easier time healing you.
Also when people say things like get x stat to y rating it is always only a general guide. Best thing you can do is look at the DR graphs/formulae yourself and work out what you need. Furthermore, do not get accuracy as a Powertech tank, simply pointless and you are gimping yourself on mitigation,
- Rapid Shots; would need 20% accuracy increase to never miss on a boss and you are not relying on RS to get threat or do damage it is something you do to dissipate heat.
- Rail Shot; that 1 or 2 missed shots per Op isn't gonna be a game changer.
- Unload; Incredibly situational, only used to stun standards and get threat on far targets when tanking immovable trash, never used as a rotational ability
No other abilities benefit from accuracy.
EDIT: realised you are an Imp so I changed the terminology