I dont need to hold down a mouse button to look around. I just push the mouse left or right and the view turns left or right. press the right mouse button to go into 1st person view and right mouse button to leave 1st person view (so you can use the mouse to select icons etc).
Dont know why yours is as it is.
The two thin lines "at 11:30" ummmm not 100% sure, but they may be sound contact lines??? e.g. your hydrophone operator has picked up to sound contacts, one at approx 350 degrees and another at 355 degrees.
Edit :- Upon reading the manual i see that the left mouse button needs to be held down if your not in "true 1st person perpective".
To enter "true 1st person perspective" press the right mouse button.