Here are some seeds for lazy people or for some people that just want some strategic location to build their mansion. Don't worry about coordinates, you spawn literally right beside them. Note all of these are tested on v1.6. It is said that all of these seeds do work at anywhere from 1.1 to 1.7.2. Do not try it above 1.7.2 as you will mess up the biome generations.
Wow. I did not expect someone to do such a deep research. Thanks,for the info anyways. For the structure part, I specifically used the version that is stated for the seed. Supposingly you are correct as there isn't much changes since 1.7.2 but it is best to follow the original version. For the first, which is the stronghold. There isn't actually,any library or stronghold structure beside the portal which is strange. I suppose your explanation of generation error explains all and maybe the library is at the same coordinate but a lower y-level.