I don't think auto thrusters rewards good flying. It's just insurance. The opening round of combat is most likely taking place at range 3 so you're getting free evades to help stay alive longer. Other than that it's insurance against turrets because turrets are the natural counter to arc dodgers so it helps them stay alive a little bit longer.
There's no "most likely" range for the initial exchange, the range of the initial exchange is something both players have control over, not based on random chance, and with both sides moving towards each other in a single turn, ships can easily go from range 5 to range 2 or even 1 without boosting. 2 ships at range 5 of each other will be at range 2 if they both just move 2 forward. The range of the initial exchange is something both players can influence, and something one player can dictate easily if the other player thinks it's based on chance. I would suggest searching "x-wing rule of 11" on youtube for more info on controlling the range of the initial exchange.
Good Interceptor players can create consecutive turns of range 3 exchanges before disappearing out of your arc by utilizing the Barrel Roll. Strafing is an important Interceptor tactic to be able to arc-dodge while avoiding a block.
Interceptor articles love to show pictures of Interceptors starting slightly to the side of their prey's arc, in perfect position to dodge their arc without any threat of being blocked, but you don't actually start the game there, it takes intelligent flying and deployment to put your Interceptor into that position.