Server (Apache, PHP and Mysql->MariaDB) tuning will take care of 1,2 and 4. 3 is tricky on the server end, without modifying Moodle.
I can place b/w restrictions in directories containing files, large and small, allowing a speed burst that would cover small files.
Relevant Skills and Experience
I run a web hosting service, work here full time, and have extensive server experience. See my profile for user feedback. I always forget to add "Apache" to the category when I do server work, thus the low number.
Proposed Milestones
$5 USD - New employer to Freelancer - Full account setup milestone.
$245 USD - Server optimized and speed restriction implemented in storage directory.