Encoding shouldn't be an issue, as long as proper conversions between UTF-16 and UTF-8 are done.
You should also reach out to the developer of the name changing plugin to add name change logs to your database.
These files are included with the source code of the API, which can be found here for A:SA or here for A:SE.
You need to properly include the headers and the library file when building your plugin, otherwise it will not compile.