Sorry- I thought the fact that I bolded parts of your post that were not bold would make it clear. What you missed was, you either get a large world or you get to feel like you make a difference. As the game gets more balanced, the ability of any individual to affect change in a large group diminishes, Certeris Paribus. You can't make any more than 1/40th of the contribution of your team of 40 in a 40v40 brawl.
Back to the world of Southshore Raids or even the old TB, it would be 1/100th. Even you admit that you want to feel significant.
So you don't get both, assuming you want to fight at your level.
And there's a reason so many things are instanced, and it's not because they started out instanced.
Seriously, go learn about EvE. Best World PvP Game out there.