But if I've missed something from the original Greek or Hebrew texts please let me know.
i think what you're missing is a pretty subtle point, and not so much to do with the language. it's more to do with the implications of the text, and context.
god did indeed give them very specific directions. those directions, evidently, led them into a bottleneck such that their only way forward was across a body of water. and the egyptians blocked the way back. for all intents and purposes they were
trapped, and by god's own directions and actions. all, evidently, as part of a demonstration of god's power. god is setting it up so that only a miracle
will save them.
this is quite consistent with the rest of exodus, leading up to this point. pharaoh is quite content to let moshe's people go, until god hardens his heart. then god sends a plague to punish egypt, a miracle to demonstrate that god is in total control. he does this ten times
, each time with pharaoh relenting, until god hardens his heart again. god is essentially screwing over the israelites, intentionally, to prove a point.
and this is the culmination. he traps them at the edge of a sea, with the egyptians ready to very literally kill them, hardening pharaohs heart one last time... and then provides a most illogical escape route. right across the sea, on dry land. and then kills the egyptians, for good measure.
it's all building drama. it's part of the story. the only reason they weren't
trapped was god's miracle.
now, far be it from me to support buzsaw, but if you're looking for geological features, they should such that there would be no escape route. of course, i think he's looking entirely in the wrong place.