Aislinn to the rescue! Well, she couldn't rescue most of the plot of that movie. Some things are beyond help.
As for Alli and Clare, I think it's the core friendship on the show right now, at least among the girls. We should see lots of them in S10, if not the remaining episodes of S9. Sadly, that probably means we'll see some cracks at some point in their relationship, but I feel confident about them for the long haul.
I agree about them in Heart of Glass, I loved that episode and they were among my favorite parts of it.