|Almost all new eide drives and controllers are independent and you can put both on the same cable. Been like that for years.|
Yes, you can combine them. Different ways to make it appear to the user that the space is contiguous. Might look at lvm.
I think one can also mount them to the same root maybe. Never tried that.
1/3 of highway deaths are caused by drunks. The rest are by people who can't drive any better than a drunk.