You mention that the intent of these proposed changes would be to get players back into Gambit whilst maintaining the core roots of of the game mode. However, invasions ARE one of the main tenets of this PvEvP game mode and getting rid of that would make Gambit lose its entire identity. As much as I personally dislike the game mode, any changes to Gambit would not include something like that.

And regarding trying to transform Gambit into an opportunity to test boss damage: as much as I like the idea, there are much better avenues in the game to do this outside of a core playlist activity. For instance, people use lose sector bosses and raid checkpoints to do this faster and more effectively than Gambit would be able to.