I have began to watch Zeven_Na's replay reviews on YouTube. And things that gets repeated over and over, in those I have seen so far, goes as follows:
-no specific good gun.
The strength to the light tanks are camo, view-range, and speed/manouvreabillity.
And then it is to be on a distance outside the 400 meters, if not more.
Finding someone in the late game in a light tank, you have to surf the ridge-lines
Despite the tank you drive, or your opponent are in, you tip the battle more to your own side, by limit the amount of guns that can shoot at you. Facing let's say a medium, with an arty on distance support, it's for the better to you, to take cover between for example houses. That's why city maps like Himmelsdorf are so much hated for arty players. The many houses, decreases their options to 1) position properly and more important 2) position in order to help out the team the best way.
Resetting the enemy capture
To reset the enemy capture is all fine. But then look at the time you have next to re-locate. A full reset is optimal. Driving more manouvreable tanks like lights and mediums, you most likly have all the time it will take to capture, in order to relocate, and be un-predictable to your opponent.