Well said and considered Mark.
Perish the thought, the purists will howl.
Box some steel girder "posts" in some wood material which looks like posts when finished.
The steel lends itself to vertical growth on the same axis.
And don't tell any of those guys in NH or MA what I said
Keep thinking and analyzing. Some solutions like your creek water gathering are sometimes hard to trip over. recommend you get that water tested before you touch it.
