Fix broken PHP report script

General information for the website: Details below
Description of requirements/features: We got PHP reports table and chart system from a freelancer and many things do not work - we would like to hire a freelancer who can fix the issues. Everything is in PHP without framework - grid is JSPlatinumGrid and charts are Highcharts.

Issues known so far:

Queries are querying, updating etc on all data but should only work with current user

Emailing is not working - needs to email table as CSV and Highcharts as image (PNG or JPG) - NOTE, emailing Highcharts requires use of PhantomJS, it will not email natively

Method of choosing fields is too complex - needs to be simpler. Hard to explain but this doesn't feel like a big piece of work, mainly layout based using JS to display relevant settings

Needs to allow display of sum, avg etc on tables - grid supports this but it doesn't work

Need to allow better filtering on fields - at moment can only filter on included fields on table and cannot filter on chart at all and can only have two filters. Should be more filters , allow to filter on any available field and allow to choose values for filter from database lookup

Currently can only create reports, also need to be able to edit existing reports

There may be other little things broken as well so bear that in mind.

NOTE: This script does not work properly hence why I am posting this job - do not take this job on if you expect a script which works fully and which you just need to make a few tweaks to. The code is messy but that is why I need someone to fix it for me.

Also you cannot have access to the server, database nor will I send the whole application / all the code in the system - I will send you a version of the standalone script and the necessary MySQL tables which are working in my environment and you will need to work from those.

If either of these seem unreasonable etc then do not bid - server and other code access etc is NOT an option.