Just wanted to make sure I got this interaction correct. Relevant cards

http://xwing-miniatures.wikia.com/wiki/Advanced_Sensors

http://xwing-miniatures.wikia.com/wiki/BoShek

IF a ship with Advanced Sensors (Like the Tie Silencer) is touching a ship with BoShek. BoSheck resolves, then the owner may choose to use advanced sensors. Because BoSheck doesn't reveal the maneuver, he just looks at it and makes them rotate it?

Yup. You change the maneuver, then you may advanced sensors before you reveal the new maneuver.

So for myself, I would say that yes Boshek always goes first since his card says when the ship "activates" which I would take happens as the first instance as soon as the ship gets its turn during the Activation phase.

However, there isn't a detailed timing chart for activation the same way there is for attacking and the very first thing that normally happens in activation is revealing a maneuver. So you could perhaps argue that since Boshek and AS both trigger before a dial is revealed then they have the same timing window. If that's the case then they would trigger in initiative order.

Now if I was TO and someone came to me I would say that since they're phrased different then they're clearly intended to mean different things and Boshek should definitely go first, but it wouldn't be the first time FFG used different descriptions for the same thing, so there's a small gap for a rules lawyer wedge there.

Again, just to be clear, I think OP has it correct but is good to acknowledge a potential counter argument.

Correct. Bo Shek happens stricty before AS.

I'm pretty sure this is one of the reasons Boshek says "look at" instead of "reveal."

19 hours ago, thespaceinvader said:

Correct. Bo Shek happens stricty before AS.

If he didn't, then an advanced sensors ship could barrel roll out of contact, avoiding being in contact at the point Boshek triggered.

"When you become the active ship" triggers (like threat tracker) will trump anything that doesn't refer to the ship activating (hence the point of threat tracker, which is meant to let you avoid being in arc to be chosen as a target in the first place).