Think I'd remove the lines related to sessions. Moodle has a setting for using the DB or files. If files is chosen Moodle should create a sessions folder in the datafolder for the Moodle and it is there that Moodle writes session information.
Remove:
session.save_handler = files
session.auto_start = 0
session.bug_compat_warn = 0
As a general rule, one should add/use only what is needed/allowed on a shared system and not what is desired.
To see how PHP is configured, create a phpinfo.php file that contains the following:
and then access it directly with browser. That shows the default/main php settings for the shared site.
On some shared systems, have read that users had to put a php.ini in every directory pertaining to uploading files with only the those items related to post and max.
Mind disclosing provider? Sometimes Google is your friend and one can find a customer forum with postings where someone (a fellow customer) has shared their solution.
'spirit of sharing', Ken