Usman Asar

Paul, keep web folder permission as default (read only), for dataroot folder, yes give write permission to IUSR, else moodle wont work.

I have a tutorial uploaded with video, you may have looked at it before HERE. Have you followed everything like mentioned in the video?

Michael, moodle 3.3 only will work perfectly with  PHP 7.1.x, for any previous version use PHP 7.0.X

Joseph, how many boxes you intend to setup?

You can use NLB (Network Load Balancer) to set up multiple servers, but NLB only responds to heart beat, alternatively ARR (Application Request Routing) but what if your ARR goes down? so for a high availability environment you'll be setting up combination of ARR and NLB, keeping database on 2 boxes (master and slave configuration).

in addition, you'll be setting up DFS-R (Distributed File System - Replication) to share the moodle and moodle data folders across all servers.

any more questions, feel free to ask (keeping in mind due to some busy schedule, I will be replying with a slight delay)

Jhon, site has some issue, therefore it's developers job to fix those database failures, you can either wait for sometime before site owner fixes the site. you can however meanwhile look into this link to learn about moodle. https://elearningindustry.com/105-free-moodle-video-tutorials

Howard, he is talking about www.iteachwithmoodle.com