stuff of mine
There is limit to everything, I don't want to repeat the same arguments if nobody's reasoning was strong enough to change my views. The problem here is obvious lack of knowledge and experience on pvp by anti-pvp'ers, some remember old days when they were doing some pvp, others talked to pvp'ers, etc... no pvp guild experience, no emotional experience from pvp'ing... it's hard to prove something when people are not on the same level of understanding. I see the opt out of pvp or no XP loss only with HUGE penalty in progression, so players would have to choose between risk free slow progression AND higher risk & faster progression. The sense of accomplishment comes from taking higher risk, don't take in-game defeat personally, it's all about emotions and taking risk to lose hard earned.
I'm with you on there's only so far one can push one's point before becoming a broken record - though I don't think it's necessarily a case of "levels of understanding", or at least not in every case - most of it is actually about entrenched viewpoints. I can state, with great certainty, that I understand pretty well what constitutes competition (I will provide you with a bit of my background here, for context, nothing more: I have played StarCraft on a national competitive level, chess at the club level, table-tennis at the university club level, Magic the Gathering at the national level...and all the other stuff I mentioned in my previous post - and I always play to win! Is there any ther way? So you can see I'm no stranger to individual competitive gaming. I've also refereed some, and I am a gaming journalist with over 12 years' experience. OK, credentials sorted, yes? Enough of that, then) So back to my point - I understand what constitutes competition, and I maintain that the PvP mechanic in FS is fatally flawed - it is not inclusive or immersive enough, and is not by any stretch of the imagination a test of skill. The way I see it, it's about whose patience lasts the longest. I by no means argue for PvP to be excised, though - that would be a terminal mistake, in my opinion.
Personally, I am not in favour of an 'opt-out' mechanic - that is the polar opposite of inclusiveness. So if such were to be implemented, yes, I agree, it would have to cost heavily! And for those who like "real world" comparisons (flawed as they are), it can be said that isolationist policies have always come at a severe cost to development.
As for XP loss being taken out of PvP, that I certainly DO agree with - and seeing as it would affect EVERYONE equally, there would be no need to penalise progression. However, I also second Luisspamer's idea of enhancing the PvP experience by adding XP GAINS for vistories. That effectively would transform a negative into a positive. Now instead of non-PvPers feeling abused and not wanting to get embroiled because the cost outweighs the benefit, they have the follwing choices: 1. move along with no real harm done (except perhaps some gold lost - no problem with that) and the PvPer having gained something from it (XP, gold, prestige, rating - wow, that's quite a list, innit?), or 2. climb into the fray and get some back!

Now wouldn't this be a more appealing set of options all round?
"And the man in the back
Said 'everyone attack'
And it turned into a bar-room blitz!" (or is that "ball-room"? Can't remember...)
Regarding your "higher risk for higher reward" - I absolutely agree (and that's why I think the attacker should risk DOUBLE the XP [if XP loss were to stay, which it doubtless will] and gold, considering that every advantage belongs to the attacker.)
Thank you for providing me with a post that I could respond to, and which I had to think about.
/bows