Banzai, that was a much more complete and eloquent analysis than my brief attempt. I should have added an assumption that the spoke preloading greatly exceeds the slight incremental load of hanging the bike from the rim (not to mention the more significant incremental load of normal loading & impacts while riding), therefore the incremental stress is inconsequential. If the spoke material is going to creep, then spokes would be constantly losing tension at a very noticable rate, almost as quickly while the bike is static as when it is ridden.