Try development version of AnsPress from Github.
I will check.
It was a bug of category extension, but it has been fixed yesterday. Download from here: https://github.com/anspress/categories-for-anspress
No, anonymous voting is not possible yet.
Tags suggestion issue has been solved, you can download master branch from GitHub, https://github.com/anspress/tags-for-anspress
You cannot override a function like that. instead use this: https://gist.github.com/rahularyan/f2bc0d8443b18cdc2b8a