Link2SD proper usage I have a 64 GB micro SD card.
I partitioned 1.2 GB as Ext2 with Mini Partitioner (highest option was about 4 GB).


This is great and all, but from all of the literature I've read, Link2SD seems like it would utilize the entire SD card, not just that second partition.

If what I'm seeing currently is correct, the only thing that Link2SD does, is give you an extra GB via the Ext2 partition, and imposes a dependency so that you're never able to actually remove the card due to the links.

I believe my thinking is wrong so any help is appreciated.
The literature you read was wrong, then. Link2SD only uses the extra partition. The main partition is still mounted under /media/sdcard or somewhere similar.
With Link2SD, you cannot physically remove the SD card, but you can mount the SD card on the computer. The second partition does not get mounted, so the apps are still accessible while the standard partition is mounted on the computer.
If you want more space, you can always repartition your SD card manually on your computer, if your version of ClockWorkMod (CWM) doesn't have the size you desire. GParted on linux is a handy GUI, and there are apps for Mac and Windows as well.
And you can still install apps to your SD card the normal Android way, though the dalvik cache and other data will still use up the internal memory (which is likely limited in your case, as that is the reason to use Link2SD in the first place).
Purpose of Link2SD
Here's an hypothetical example+. You have 180MB free internal memory. You have a standard 16GB SD card.
When you install an app to the SD card, 10%* of the app is actually still on the internal memory. So when you have installed 1.8GB of apps, you run out of internal memory, even though your external SD card could hold a bunch more.
In comes Link2SD. Now, your SD card is actually 12GB standard and 4GB for linking. New apps get Linked, but this time 100% of the app is moved, so you can install 4GB of apps instead of 1.8GB.
You shouldn't be limited to 4GB, either. ClockWorkMod (CWM) may only list 4GB as the maximum size, but you can use a computer to make the linking partition as large as you want.
*Made up percentage. It varies by app.
+Not so hypothetical. With my old Optimus V, this was almost exactly my setup.