The only odd thing I find about his portrayal of people's mothers is how often they see them. If anything, I think his companions tend to be more in contact with their parents that a lot of people are after they leave home. (Partly because Rose and Donna still live/d at home).

I think the relationships are supposed to be fairly positive.

I liked Donna a lot in this one. And the cute alien babies. You can also see that the Doctor has been 'humanised' from his contact with Martha last season -- he tried to save the Nanny at the end, after all. I wish Rose hadn't shown up. I'd be perfectly happy never to see her again :P