Hello Mate,
I am an experienced Web Developer as well as SEO expert also having 6+ years of experience.
I Can optimize the loading speed and other on-site SEO, as well as I, am also expertise in off-site SEO work.
Yes, I can easily Combine images using CSS sprites, Leverage browser caching, Minimize request size and optimize it.
Recently I have done lots of work for my clients related to this, you can check my latest work here as well:-
https://www.freelancer.com/u/pradeep9266?w=f
Please ping me on chat for further discussion.
Regards,
Pradeep P.