(Since I work with disaster contingency I am well into the nerd cave when it comes to this.)The sad truth is
"the plan can never be more advanced than the commitment to contingency planning of the least interested part." Meaning I can make a perfect plan but if my wife will not learn it and go through it, it will likely break down to the smallest common denominator anyway.
My planning is larger than what my wife and kids bother to learn and find out about, so. Will try to answer your questions from the standpoint of my own plans though.
On coms:First try cell. Then text, then try wireless and send an email. Then if land lines are available or you get through at all on the cell, call home and leave a situation report on the answering machine. This might be the only reason I still have an answering machine that kicks in after about 30 signals..
On what to do:Get the kids, get home. Smallest common denominator. If the home area somehow is demolished, get kids, move to location B. If B is unavailable, C etc. I will not try to guess if my wife or parents have picked up the kids before me, until we hear otherwise everyone is heading for the kids. If the kids are not at school/daycare, move to location A.
It has to be really simple, advanced flowcharts are worthless without practicing. Getting the wife and kids to practice anything but cooking, xbox etc can be a challenge.
Scenario specific:The smallest common denominator for disasters are: Bug in or bug out? Ie, is the area secure enough to remain, will you be better off "sitting or hitting". So for scenario specificness I only make a difference for scale. If the house is destroyed but not the are at large, move to location B (parents house) abt. 1.5km away. Barring that you go to C which is staging point for bug out route A. We have a fire evacuation plan, etc but for a "get home" scenario those play into this.
On kids:Kids are our responsibility. We get them, if we cannot find them and no proof of pickup can be found, go to "missing person" plan and look for them. Plan as far as kids know: Stay put, go with the people you are allowed to go with. If moved involuntarily, leave a trace or message.
Backup plans are as simple as possible. Only place to go first, second third etc.
The only plan we carry is a laminated card (With all phone numbers, contact info and numbers that usually reside in cell phones nowadays.) taped under the inner sole of a shoe. I made about 30 so I put them in all the shoes.
My plan is more like a risk assessment P.M. so including it would be lengthy and in Swedish.

But since I have to break it down to simple simple, I go with range and geography. These are the things that make your decisions for you. How far are you and what is the terrain? How far reaching is the disaster/accident and what is the geographic risk ratio as a result?
For instance:
Flood: Bugging home.
Myself: Crossing 1 of 4 possible bridges, required for BH [Bugging Home]. Possible miss of rendezvous is high since bridges might be affected where I am at.
Wife: Crossing 1 out of 2 bridges, unlikely they will be affected enough to slow her down. She could swim it and be at the kids school, on foot, in 30min.
Kids: School, unaffected by flooding due to terrain.
Home: Unaffected, bugging out unlikely in case of flood.
Check flood supplies 1 in 3 years due to shelf life of some items. (just my example´and food is not included in my flood supplies.)