Was the eye implant to allow sensing whatever this former member of the Mercenary Army Program was looking at by remote observers? Has this been removed?

The answer is "yes" to both. The extraterrestrial technology is varied and many types of implants can be used for high functioning high-level operatives. Being able to see through their eyes literally, is an advantage for them in carrying out many duties, as their controllers can virtually follow along in real time and experience what they are seeing, and react accordingly to make nuanced refinements of their instructions on the spot to deal with the unfolding events in the most efficient manner, and therefore be prepared for any contingency. This allows maximum control in the moment for the recruit to be deployed in the most effective way without extensive prior briefing that lets the recruit in on the overall plan and its true intentions. This is the reason that the recruits must be trained to carry out any instruction, no matter how excessive its implications and consequences, without any thinking on their part. They are, in effect, more like a robot directed to show up at a location and then instructed from one moment to the next to take a series of actions without second thoughts, without any concern for personal safety, nor the safety and comfort and rights of others. This makes them a quite effective weapon.