Hi, As Discussed.
1) I will use a good caching plugin that will work, I am sure.
You have listed five listed 5 speed test tools, these are not same, different for few issues. For example, google page speed has mobile loading scores. few are commons tools. important are google, gtmetrix, pingdom.
I will score it up to 80 to 85 on gtmetrix, and pingdom. commited. but I will optimize all possible things, may be will get higher scores.
Mobile score on google speed will be 75 to 80 and
Desktop scroe on google speed will be 80 to 85.
you have external scripts connected with your site, facebook, google, and otehers, total 20 urls, if possible reduce them.
2)
All mentioned SEO issues will be fixed ( except arabic meta)
3)
Ans. SEO will be done for all English pages/post.
4)
Ans: I will create sitemaps and upload to search engines properly.
5) Will be done accordingly.