So, with regards to setting things to null to free their memory, ints, floats, etc. can't be set to null, but their memory does not normally need freeing.
I had another look into this and I'm cleaning up some of the tricks I pulled hoping to save on memory leakage with this knowledge.
It does strike me that function calls leak rather a lot of memory, even for functions in which nothing gets defined beyond their parameters (which are primitives, in this case). Is there any way to avoid this? Maybe I should leave it be and wait for the next version to see if the proper GC addresses the issue?