Fix Shopify Conversion Tracking, Add Store Review Schema & Optimise Core Web Vitals

My Shopify store is already running Google Ads, Microsoft Ads, and Meta Ads, but the purchase-conversion data is either missing, inaccurate, or throwing tag errors. I need a specialist to audit the current installation and make the “Purchase” event fire consistently across all three platforms.

Scope of work
• Inspect existing Google Ads, Shopping, Analytics & Search Console tags, Microsoft UET tag, and Meta Pixel to locate why purchase events aren’t recording accurately.
• Correct or replace any broken snippets in Shopify’s theme, Google Tag Manager, or native channel apps—whichever is causing the conflict.
• Verify that only 1 Purchase action is tracked per conversion including the conversion/purchase value (Add-to-Cart and other standard ecommerce events are useful but not mandatory for this task. No Sign-up tracking needed).
• Test each platform with Tag Assistant, UET Tag Helper, and Meta Pixel Helper, then run a live test order to confirm revenue, currency, and order ID pass through.
• Document the issues found and the fixes implemented in a short handover note so I can maintain it after future theme updates.
• Add the schema snippets to Shopify theme specifically for store reviews (some product review schema already working via the Fera reviews app) to display in the appropriate store/website info search results.
• Provide a test showing the schema is working correctly once installed.
• Inspect Shopify theme code and advise on best practice or missing schema, implement if I advise it's required.
• Optimise Shopify theme (not via an app or 3rd party solution) to achieve improved page speed results, score over 90 for performance & accessibility for both mobile and desktop.

A clean, fully functioning purchase-conversion feed for all three ad platforms is the deliverable, along with screenshots or logs that prove the events are firing.