Babies hold still in new circumstances that may be frightening to them to take time to adjust and avoid attracting attention from predators- and other chickens that may aggress on them, since they're tiny strangers in the territory of an established flock. Any situation that's new will cause them to take their time, they'll move at their own pace.
When chicks are not fully feathered they still need supplemental heat and will hold still and huddle together to conserve heat. At one month old even in 70-80F weather outside if they look cold they should be let back into their warm enclosure, since they don't yet have good protection from breeziness that slightly older birds will shrug off. The base of most of their feathers is still being formed and/or is encased in their feather sheaths, allowing for more airflow near the skin than a properly feathered bird would experience, who would have loads of tiny, downy fibers at that level in their plumage, which trap air and stop drafts from whisking away the heat right next to their skin.
To prevent mushy crop issues make sure you're taking their feed up a couple hours before bed. Give them access to feed for 12 hours out of the day, and remove their feed after that period until the next day to give their crops ample time to empty over night, keeping food from lingering and having the time to turn sour.
Watery poop can be normal. I feed my chickens wet fermented feed and fresh fruits as treats, so their poops are softer than dry-fed chickens' poops and are occasionally quite watery a short time after eating a particularly moist morsel of food. To be clear the wateriness is urine that surrounds the poop solids, unless the poop is a cecal poop. Cecal poops look like terrible diarrhea to us humans, but are perfectly normal when emitted from a chicken. Here's a good article on what chicken poop is like:
http://www.the-chicken-chick.com/2012/02/whats-scoop-on-chicken-poop-digestive/
