In
Sibley's blog there is a lot of discussion about Redpoll identification. It is pretty complicated and intermediate-looking birds can probably not be safely identified to species.
With this information my comments about the picures are:
1. Cannot determine from picture.
2-3. Same bird? Light-colured male Common Redpoll, on the border to being intermediate.
4. Male Common Redpoll (Heavy streaking on undertail coverts)
5. Cannot determine from the picture, undertail coverts looks light with only faint streaking, but this might be because of the angle. Might even be the same bird as in 2-3?