Hello,
As per your requirement for wordpress site,you want some changes to be done due to some prolblems.
I will do it very well and provide you full satisfaction and fulfill all your requirements.
The first problem is with the language so we will use "STELLA"
Formerly known as Rosetta, Stella allows visitors to your site to quickly and easily switch between multiple languages on the front-end and you can add or remove translations on the back-end.
It is easy to use straight out of the box, just write a post, fill in the post content for each language (different tabs allow you to switch between translations) .
Visitors to your site can also switch between languages. You can set up the Stella language menu wherever you like with a widget.
The next problem is with Permalinks we will solve the problem it would be better if you provide me the link of your website so i can do more analysis,understand the actual problem and provide you better solution.
Tech suggestion-
Front end-Wordpress
Back end-My SQL5
Designing-HTML5,CSS3,Bootstrap3.0
Time estimation- some weeks for testing and hosting on the server.
More details of project i will provide you step by step in further discussion.
You can contact me over on skype for better understanding of project.
I hope you will consider me for further discussion.
Regards
Nupur Saxena
Ebullience Tech