Magento 2.1.4 based website speed optimization and troubleshooting. -- 2

Magento 2.1.4 based website having issues below which needs to be fixed. 1. Site load speed in extremely slow, i need gtmatix grade above 90, with lowest request, without compromising any features of the website. I need lowest CPU and Ram usage. 2. HTML Editor sometime works, sometimes not… works in firefox… not working in chrome… i want this to be fixed. 3. Cannot install any extension through system > web setup wizard. Its taking hours and hours without any installation. Please note that i’ll not provide any ssh, cpanel access. i’ll provide Teamviewer access in order to do all the job through teamviewer, as i don’t want anyone to gain the access and copy all the files.