When a walk becomes twice the work-out

If ever I want to get not only a physical but also a mental work-out, I just go on a walk with my kids.  Physically I get to do plenty of stopping and starting as I wait for laggards, plenty of twisting and bending as I help the little ones get back on their bikes/scooters, and even a few wind-sprints as I race to keep up with the ones who are darting out into the intersections.

But beyond that, my parenting skills get tested at a consistent and rapid rate.

Throughout the walk, many situations jump up which necessitate my mental abilities to stay on their toes.  It seems there are countless times when a question is thrown at me, and I don't know what the right answer is! As examples, here are just a few of the exercises that I went through on our walk to pick up some groceries this afternoon:

Exercise #1:
A child wants me to detour to a pond where he can show me the "coolest thing ever."  So do I oblige him in this?  Over and over I've heard/read advice about how important it is to stop and smell the roses with a child, because they just don't stay little long.  Then again, if I stop and detour every time a child asks me to, we'll never get anywhere, I won't get the groceries I need for dinner, and then we won't eat.  Plus, doesn't following his agenda promote a child-centered mentality?  But then again, he's just so excited about whatever the thing is....What to do, what to do??

Exercise # 2:
I encourage the kids to take a little short-cut, which means crossing the street not on the cross-walks.  They start to question this and I realize I need to answer them.  Do I tell them it's ok to not cross on the cross-walks sometimes?  Will this get them in trouble in the future?  Or do I tell them they should stay on the cross-walks, which means I just broke the rules and, by example, I may be encouraging them to break future rules??

Exercise # 3:
A child starts refusing to ride his bike the rest of the way.  Do I encourage him kindly to keep on keeping on, and give him the occasional push, cheering him along the way?  Or does this promote coddling and a child-centered mentality?  Do I practice tough love and tell him I'll just see him at home whenever he gets there, and keep walking?  Will the neighbors call Child Protective Services if they see him screaming there by himself??

Excercise #4:
A child now claims that riding a scooter is too hard and he doesn't want to do it anymore.  When I don't offer to carry him home, he stubbornly refuses to ride the scooter, but carries it instead.  This, of course, makes him go much slower than normal.  Should I let him fall far behind so I can keep up with the other kids and make sure they cross the road safely?  Or should I stay back with him to make sure he crosses the road safely??