Partition Format on Mac
Yes, you are correct. /Volumes/(name) is the mount point.
Mac OS Extended (Case-Sensitive, Journaled) is the best case-sensitive option. I'm assuming you know what you're doing with case-sensitive partitions.
The biggest disadvantage, maybe, of creating a separate partition is that you can't use Boot Camp if you have more than one partition on your startup disk before partitioning for Boot Camp, meaning that you can't use Boot Camp at all if you only have one hard drive on your Mac. You said that you want the separate partition for Linux; do you mean that you're going to run Linux in Boot Camp?