Not even 24 hours further and 8 submitted styles are already validated (prosilver is by default anyway).
Anyway, the answer to the topic_title question is: partially!
The 3.2.9 version will probably be more suited but it will still be only: partially.
Generally the style you use should be specifically tailored for the phpBB version you use.
Spelling is freeware, which means you can use it for free.
On the other hand, it is not open source, which means you cannot change it or publish it in a modified form.