Didn't know you could also upgrade ablities, that upgrade definitely makes the wizard ability really good then. And you're right, I forgot about Dex giving you a bigger hand at the start, which is not an insignificant buff. And yes, your explanation makes sense - might be that the strength of those stats are simply not as obvious at their first impression.
Oddly I haven't encountered any crashes since either, so sadly cannot provide more information - might've been just something on my end too. I'll let you know if I'll encounter any other bugs and best of luck for the future!