[The Might]

Legate, you again seem to totally misunderstand me.
If you would read my first post again you'd notice that I did not attempt to show this alternative could have been better or at least as good as what happened, but that it could have been taken as a valid option into account.

There still were Druedain living in that area, and if we were to simply speculate they were quite similar to the woses met by the Rohirrim, they would have probably helped the Fellowship, as they too fought the Orcs. From there it wouldn't have been a huge way till Pinnath Gelin, which we know was inhabited.

You speak about all the disadvantages of this route compared to the others, but you don't seem to take its great advantages into account.
No Moria, no Anduin with the eastern side watched by the Enemy, no all everything.

As for crossing Anduin, well, Pelargir comes to mind.

All in all, what I want to say, is not that this would have been a better alternative in the end, probably not, but was definitely an option that could have been taken into account.
I doubt that Gandalf planned what happened afterwards, for example Merry and Pippin's coming to Fangorn.
Their way through Moria could have been ever more devastating had the battle with the Orcs ended otherwise, the Ring could have been lost in some pit together with Frodo.
So I wouldn't be so hasty to clearly say that the road they took was the ideal one.