About the Russian visas, the usual technique is to get them issued for dates that bracket your actual travel dates (to allow for travel delays). Any competent TA will automatically do this, and the Russians play along for up to a week before/after. Too bad you didn't have good advice on getting the visas. You'll know for next time.

About the OW awards, AA does offer other award types which do allow rerouting (while OW awards do not); however it would have cost quite a bit more Aadvantage miles to redeem those awards instead. So you traded off a cheap award cost with lack of flexibility -- then complain about the lack of flexibility (or expect AA to provide flexibility for "unusual circumstances"). Now every reroute has some sort of "unusual circumstance". I've had revenue tickets which became invalid due to visa problems, and it cost me thousands of dollars to fix it. I wish the OW rules allowed for more flexibility, but they don't and most of us live with it (or don't use those awards).