Pathfinding leaving dupe "stranded"

A dupe will not leave a piece of land if it has to walk though water.
You can make a dupe build something there which got them there in the first place, but the dupe will never leave there unless you dig out all land underneath them to dump them in the water or build a tile bridge.

I've had this happen with 1 tile and 2 tile deep water.

Another issue is the dupe will build or remove something like a wall or floor that leaves them trapped from the rest if the base, ie: built|removed from the wrong side.

Dupes will also deconstruct things in odd orders leaving pieces just hanging around that you have to build something else to them then un-build what you just build to get rid of the remaining pieces.
Dupes will trap themselves on these pieces and if the piece is being deconstructed the dupe will drop itself into whatever is below.

These issues account for approximately 90% of all my dupe deaths..., somewhat frustrating that they are committing suicide all the time because they don't consider the order of things or are just scared of 1 or 2 tile deep water.