Tholians as of "The Tholian Web": poorly understood, territorial, and hostile to the Federation. Spock *in particular* even seems to be aware of them!

As we know virtually nothing about them in canon, they wouldn't really need to change anything substantial about the plotline, and they wouldn't need to tie themselves in knots trying to make it fit with "Arena".

I would also accept "arthropology"

I saw that movie at the precise right time and place for it to make a *big* impact on me. I've been meaning to watch it again for a while now!

line should *obviously* be directed towards Sacramento and the thought of giving Oakland a second wye sounds like a bad idea.

What's interesting to me is how it looks like they've intentionally left space for the third track along Broadway that would eventually enter service?