As for Homura's attitude, I think she's just jaded. We don't actually know how many times she's done that stretch of time over. After a while, I'm sure anyone would find it hard to put any enthusiasm into the task when you already know how it's going to end up.
I think Homura's real problem is that she's only focusing on Madoka. After all, if Madoka is the only one of the group to survive (and un-contracted), how likely is it that she'll come out of it sane? If she ends up damaged beyond repair by watching all of her friends die horrible deaths (and some for her sake), then can you can really say that she's been "saved"?