Most ideal situation is close to 50/50 on servers- the further away from that you get the worse it gets to pvp on that server, and the worse it gets the more people leave, making it even worse.
Now- immunity doesn’t make sense- but, I think the ‘no honour’ debuff you get after landing at an FP should also apply to you right after you rez. It won’t completely eliminate corpse camping, but it’d remove some of the reason to do so.
Guards one shotting also makes no sense- but add more guards that can see through stealth (they’re guards, being perceptive should be part of their job), put guards on rooftops to prevent safespotting which is an exploit and Blizzard has called it an exploit. Guards perhaps shouldn’t be stronger- definitely not one shotting people- but there should be more of them, and they should have the tools to capture wrong doers- such as stealth detection, nets, charge abilities, etc…
It shouldn’t be a cakewalk to infiltrate an enemy town, and definitely shouldn’t be as easy as it is to get into a major city. The ease with which you can enter IF and move about as a stealthed class in particular is baffling, and on the flip side being able to effectively stroll into Cairne without breaking a sweat when Thunder Bluff ‘should’ be an extremely easy to defend city (few entry points, great sight lines, if practical the ability to simply stop the elevators to prevent access when threatened).
Oh- and definitely put some elites on boats/zeppelins. C’mon, you’re going to leave the main form of transportation in a war heavy world completely undefended? Seriously?