https://enhance.com/docs/getting-started/requirements.html
All customer data resides in /var and we recommend, if your disk is partitioned, that this partition contains most of your available space.
No, if you have multiple drives it won't detect everything as 1 drive. Enhance doesn't manipulate anything in terms of drives or partitioning, and you will ideally need to setup your partitioning before installing Enhance. I recommend you do some reading on partitioning and LVM in Linux.
Enhance also doesn't do anything in terms of security around SSH, OS updating etc - it's something you need to handle. It's a web hosting panel and not a server management suite, so you will need to know what you're doing and get your hands dirty.