the first message is displayed because you are importing a package from an older version (5.5 R2 final) to a newer version (5.5 R2 with hotfix). However, there shouldn't be any problem with the import, the web part should be compatible with all 5.5 R2 hotfixes. (I tried it with the 5.5.4311 R2 and it worked well.)
The second message means that if you have already created a web part with the same code name (VimeoVideo) before, it will be overwritten after importing this one. In such a case the imported web part is marked with * sign.
If you have not created your own Vimeo Video web part before, you do not need to worry. Finish the import process and you will find the web part in the "Community services" web part category then.