But theoretically you can format it to ext2 if you want.

I personally am thinking I might delete the /opt partition and make /home the full size as I do not need mass storage device ability. Being able to properly share all that space between /opt and /home/User (whatever its called) is far more convenient. The ONLY reason they are separate partitions is to allow mass storage device ability, which you could still do for the microSD if you needed that ability.

OpenSSH will be one of the first things I install so that I can transfer data over more easily as I hate the messing around mounting/unmounting/permission denied issues you get with the mass storage controller method. That and how it cannot be accessed from the phone at the same time.