Confirmed. Note that the nether portal gets CREATED at the correct coordinates, but sends the player to the wrong ones.
Done. Note this is still a problem in 41b.
Confirmed for all snapshots up to and including 15w35e.
As an aside - at MineCon2015's recent question and answer session, Jeb was asked "When are you going to fix boats?" This was almost certainly directed at this problem, as it is perhaps THE most glaring issue in Minecraft as far as is noticable during normal play. He response suggested that he thought the asker was asking about the fragility of boats, not the syncing problem (his response was that it was WAD but that they will be adding more sturdy boat options in the future.) This may be a silly question, but are we sure they're aware of this? For me, this is the worst bug in the game!
Yes, confirmed that you do not have to use the /give command for this bug to apply. This happened with my black shield, crafted in survival - when shot by a skeleton arrow, shield changed to orange (including tooltip changing to "Orange Shield")
I really hope they don't make us wait until next Wednesday to fix this... 😞