WordPress Custom Development Issues (WordPress Codex/PHP/JavaScript/AJAX) -- 2

I have a list of issues that need to be fixed on my website. These can be easily fixed within a day with a skilled full-stack developer. As a developer myself, I am looking for someone who can provide guidance on the issues not to hand over the staging site.

I reduced the list from 17 to 8 and with in-depth details.
The theme is WP Bootstrap Starter
Here is the staging site: http://35.161.164.191


Convert Mega Menu into plain JavaScript
http://35.161.164.191/wp-content/themes/leadstart/header.php
Main JS file: http://35.161.164.191/wp-content/themes/leadstart/inc/assets/js/theme-script.min.js
replace Bootstrap nav walker with this and have it work with Bootstrap 5.0 -
https://github.com/Alecaddd/WordPress-MegaMenu


Fix the Search Filter
Code needs to be converted to vanilla/plain js as well instead of jQuery AJAX. I need also a better or proper way to replace initial search results if possible just overall cleaner code.
https://stackoverflow.com/a/8567149
https://prnt.sc/gxrJE9_GocOl
Example search - https://35.161.164.191/?post_type=any&s=01
The original instructions used to add filters are here - https://rudrastyh.com/wordpress/ajax-post-filters.html
My code: http://35.161.164.191/wp-content/themes/leadstart/search.php
http://35.161.164.191/wp-content/themes/leadstart/inc/loop-functions/loop-searchfilter.php
http://35.161.164.191/wp-content/themes/leadstart/inc/assets/js/archive/archive-search.js


WooCommerce 'My Account' page vertical tabs
'My Likes and Bookmarks' tabs has loops that need custom pagination (must be logged in)
Numbered pagination needs to be added to custom My liked posts and Bookmarks tabs and use ajax to avoid page reload/refresh
http://prnt.sc/n13Nv49CwMfv
http://35.161.164.191/my-account/
http://35.161.164.191/my-account/my-likes
http://35.161.164.191/my-account/bookmarks
My code: http://35.161.164.191/wp-content/themes/leadstart/woocommerce/myaccount/likes.php
http://35.161.164.191/wp-content/themes/leadstart/woocommerce/myaccount/bookmarks.php


Snippets Post Type Archive thumbnail generation
Programatically set screenshot taken by WordPress Mshot as the post's featured image
https://www.wpbeginner.com/plugins/an-automated-way-of-taking-website-screenshot-in-wordpress/
My code: http://35.161.164.191/wp-content/themes/leadstart/template-parts/content-archive.php


Font Post Type Single Page
Variants dropdown and font-weight are not working
http://35.161.164.191/fonts/fv-almelo-4/
https://github.com/underscoretype/fontsampler-js
Example: https://underscoretype.github.io/fontsampler-js/
My code: http://35.161.164.191/wp-content/themes/leadstart/inc/assets/js/custom-fonts.js


Font Post Type Single Page
We need to adjust font color based on background
https://35.161.164.191/fonts/fv-almelo-4/#livemodal
http://briangonzalez.github.io/jquery.adaptive-backgrounds.js
https://github.com/briangonzalez/jquery.adaptive-backgrounds.js
My code: http://35.161.164.191/wp-content/themes/leadstart/inc/assets/js/custom-fonts.js


Consultation Page
JavaScript is not working properly, it is not showing any validation on next, and clicking on next nothing happens also if we can switch to plan js
https://prnt.sc/bFw2-68cgLtO
https://35.161.164.191/consultation
My code: http://35.161.164.191/wp-content/themes/leadstart/inc/assets/js/theme-script.min.js