Never! The trooper is the backbone of any squad. Always at the front of any battle, be it attack or defense. Remove his ability to detect, hunt and destroy the enemy and you render his class useless. Also on a lighter note, remember apart from following the Squad leaders orders on attack or defense he has virtually no other way of accruing team points.
Also like to confirm that with RabidJohn as your squad leader your aways kept well supplied with not only ammo and bacta but also orders. Keep up the good work mate 

"Something something something Dark Side.. Something something something Complete!"

No you don't get team points for using the scanner but you do by following your squad leaders orders. Therefore you tend to do as ordered perhaps more than the other classes because its in your best interest. Remove the scanner from the trooper and you remove any benefit to play that class, may as well play medic or support. Their weapons are just as powerful with the added bonus of extra points for doing their specific jobs.

"Something something something Dark Side.. Something something something Complete!"

True, the scanner does give an advantage, but this was always the idea wasn't it? Woody wanted to saturate the battlefield with various scanning options so that enemy soldiers would gravitate towards each other due to detection rather than wander around the map missing each other and the opportunity for an exciting firefight.

I personally quite like this aspect of First Strike, it keeps your squad situationly aware, and is by no means an unfair advantage as the enemy should be in squads and therefore have access to the same kit. Also each sensor device is slightly different making them useful in different ways, the tracking beacon has a small range but is constant and can be left somewhere, to keep scanning a CP you have just captured and moved on from for instance to detect if the enemy is trying to retake it. Also a useful application is attaching it to a friendly vehicle such as a Walker so it then has added mobility and can help the Walker pilot detect infantry. The sensor drone has a pulse and slightly larger range and is mobile which is obviously very useful, and finally you have the Officier's sensor box which gives a wide range temporary ping, all very useful, but in quite distinctive ways.

The abundance of sensors in First Strike really helps ensure that there is a lot of action in infantry maps and helps disuade lone wolfs who now have to fear falling prey of enemy sensor sweeps that can give away their position. They'd now stand a far better chance if they joined and stuck with a squad.