Lots of crashes and exceptions

The version 7.1 has a lot of problems in the interface builder, sometimes just thinking about changing a constraint crashes it. While editing Swift code the syntax highlighting crashes almost everytime I try to call a function of an optional with the ?. operator, this did not happen with version 7.0. I regret my decision to update.
And lastly, why is it still not possible to refactor Swift code? This is an essential feature of every IDE!

TonyJStark about Xcode, v7.1