You could easily ask the same question about engines that are driven lightly from a cold start and never find one with accelerated wear.
I'm pretty sure I've said that at least twice now.
Also, my buddy's dad, same one who runs the shop and my uncles won't idle their race engines. But that's more of an issue of a solid roller as they can wipe cams, doesn't really apply to street engines.
Absolutely irellevant. 1000 psi spring pressures over the nose, with no oil going through the lifter, therefore the cam relys completely on splash, is very hard on roller lifters. Not the same with any hydraulic valvetrain. Speaking of which, why did this start with washing down cylinders, and now we are talking about it being hard on valvetrain, just because you heard about the 5.7 cam/lifter failures?
From my point of view, on a gas street engine it's not really about if it's going to hurt it. It's about if it's necessary, which I don't believe it is. If it does actually increase wear from extra time on the engine, you probably wouldn't notice. You'll be on your 57th transmission by then anyway.
It is necessary. Metal on metal parts like to be the same temp, but the absolute most important thing is that I'm comfortable when I get in. As I said, when my heated seat and steering wheel are all warmed up when I get in, but the air around them is cold, it just feels weird. It's rubs me the wrong way, like when the fluid around a cylinder is cold, but the inside of the cylinder is warm, the parts get rubbed the wrong way. I'm not worried about transmissions. Lifetime warranty = free until 60K and then $100/each for the Ram, and the oreillys brand fluid, with a transbrake and 5000 stall in the Mustang does just fine.