Martens, I like Snap-On for torque wrenches. Got 'em in different sizes, they're all good. Snap-On is really good about fixing them for free - while you wait - if one gets screwed up too.
On my early-early model, I just loctited (blue) the ejector bolts. On my newest one I'm experimenting with Nord Locks. So far, so good, but I need to set down at the Hornady progressive and crank out another case or two of ammo...... You know, just to make sure ;D
Another place to check is the gas block set screw. That having been said, if that one is also torqued to 250 inch pounds, I haven't had any problems (Thanks Terra!).
NY, this applies to both old and new style rifles. There's no difference in the barrel retaining bolt and barrel anyway. I've removed my barrel pretty routinely for what, almost 3 years now on the first one? No problems, and nothing wears with time - just don't lube the bolt threads (or, as in my case, accidentally get oil in that area).
My personal opinion is that people (and I include myself in this category, past tense) 'baby' the weapon. As in "I don't want to torque down on it THAT hard - it might hurt something!". Forget that. The torque specs I listed came from Terra. It's not a baby, it's a weapon - and it's not a fragile weapon at that either. I'll admit I questioned if I should torque those that hard the first time I put a wrench on it (funny how numbers change perceptions!) but that got slapped out of me. It's designed to be at that, so put it at that, drive on, and enjoy having no problems. At least that's my personal opinion.