Warm up info will be tough to provide, since it will depend on ambient temps, idle speed, etc.
Letting it idle too long is bad IMO, these aren't Peterbilt's running refrigeration units, like all my Cummins pickup driving neighbors seem to think. Some of them idle theirs for up to an hour in the winter!
Anyway, I start mine an let it warm up until the idle is smooth, then I drive away. If it's lumpy due to the cold start, I use the fast idle lever to keep it at 1000 or so. It will climb as it warms up.
Short trips (engine doesn't reach full operating temp) are hard on any engine. So, yeah, try to avoid them, but don't let the occasional short trip get you paranoid.
On starting, once it's warm, this thing starts better than any gas engine I've owned. 1/4 crank and it's running.
letting it idle doesn't hurt anything aslong as you keep the heat in the engine, if you have it idle with your heaters on full blast it will slowly suck the heat from the engine which is bad. but idling doesn't hurt anything. when it is -30 I let it run all day and a few nights I kept it running if it got really cold.
and for warm up, redbull is hurting his engine by only letting it warm up until the idle smooths out. I usually let mine warm up until the needle is 1/2 way up the guage and its blowing pretty decent heat, and I take it easy until its at full operating temperature. I owned a 2.6 so I know all about cracking heads and how to prevent it and the 2nd most common way of cracking those heads were driving them too cold, that aluminum sees too much heat too fast. the 1st reason was overheating them.