Hi there,
I'm a devops engineer with extensive experience upgrading, deploying, migrating and troubleshooting website issues across a wide variety of applications, including Magento. I'd be happy to help you fix these issues, but I just need a few more details.
I looked at the site -- you're right, this is egregiously slow. I wasn't able to see the errors you mentioned though, with regard to content decoding. I think I may need to start a chat somehow but I'm not sure how to do that. Could you provide more details on how to replicate that specific error?
Please get back to me with the details at your earliest convenience. Thanks for reading my proposal. I look forward to working with you and hope to hear from you soon!
Kind regards,
George Puckett