Oh no I've got some faith in this, I don't think they will be lag or performance issues, or at least nothing like they had had in modification, they're doing a massive overhaul to a point where it probably wont resemble how arma 2 servers work. They really seem set on not letting things like lag and hacking kill the game. Plenty of issues with the DayZ mod, but generally I agree with a lot of Rocket does so I don't have these worries. I was skeptical about the standalone, it's looking promising, now it's just a case of them keeping their word and if they do that I reckon it will be a great success.
As for guns I don't know, it depends how they implement it, but I am for it. Arguably these are guns you just find lying around and they haven't yet mentioned how quickly guns fatigue, how or how easy it is to maintain these guns, whether it's a building you need to go to, or loot drop you use to sitdown and clean them with. I didn't like it before that once you found a gun there would be no limit to it's use besides the ammo you have for it. Soldiers zealously oil and clean their weapons to reduce the chances of the weapon jamming, so it's plausible that a survivor would also maintain his gun.
Like I said though, they're putting a great deal of thought and carefulness into this, it would be really embarassing if they release a pile of shit. Either way it has to top both the mod and WarZ.
Fair enough, and I hope it works out for you. personally, I could not be paid to touch this with a 10 foot asbestos pole.
As to the guns and maintenance: it totally depends. Kalashnikovs have a simplicity and ruggedness that essentially precludes any maintenance (this is why it used successfully in desert warfare scenarios for extended periods) and modern guns are made of utterly different materials. Sure guns need maintenance, I am not denying that, but the time that would have to pass and the abuse that would have to ensue before a gun malfunctions is far beyond the remit of a game. What is even worse is when you get "realistic" games that have things like shotguns jam - it is simply impossible! Misfires and duds are a far more likely thing, especially given that ammo is scavenged, but a) they cause far less problems that Hollywood would have you believe (most guns, especially anything automatic, have systems built in explicitly to deal with them) and b) (and far more importantly) its just a terrible game mechanic. The way he implemented hunger and thirst was just tragic and utterly ham fisted. He, like every other muppet in the games industry, simply has no idea how guns function and so his attempts to make them "more real" are just doomed from the get go. Having this level of nonsense in crap like COD games is one thing, but in games that are pitching at realism, it just grates (that said, and I am in no way defending the cancerous shite that is the COD games, but oddly, their take on weapon handling, damage and weapon sounds is actually far closer to the mark than anything Battlefield or ARMA/DayZ has yet managed to cough up - weird).
EDIT - having read your new post - yeah, having to manage actual rounds and magazines is a "good "thing for realism, but a shit thing for gameplay. Rocket needs to have "its a fucking game - make it fun" on the inside of his eyelids in neon paint. If he pushes this towards realism it will fail - its a zombie shooter in which you need to eat and sleep - thing is, he wont remember that and he will nto stick to his design brief.