Existing web app in Wordpress

I have a website application made in Wordpress which is still in development process. There are few things I need help with, but we can do it separately and make another order after the most important one is done. That is: currently, I have a table which stores likes and dislikes from custom post types. Than, those posts are visible in feed, which you can filter by like/dislike ratio, most votes overall or by newest. The problem is, that the way it currently works is: it fetches all custom post type ID’s and than calculates like/dislike ratio and all votes. After that, it arranges them as needed. I would need you to: save the results of like/dislike ratio and total votes in table and make it fetches only limited number of posts at one time(not all). If you have better solution please let me know. This would need to be done for normal feed, for custom taxonomy feed and when search term is triggered(it loads results directly into feed via AJAX). After that is done, I would like you to create infinite scroll, because the way it currently works is not possible. After that is done, I have a few other things to do, like checking if uploaded image is valid in backend, social sharing functionality and nonces. But let’s first complete this one, and after that, we can make a new order here with specified price and things to do. Also, please review the code when you are working, and if you find something very bad performing, not secure or just badly written, we can make new order for that too. If you are interested and able to do it, than please let me know approximate price and approximate time needed for this to be done. I can link you the site with current version, I just don’t want to be linking it everywhere before it is completed.