As an addendum to my answer, I believe the 'close airport' button is introduced in the version 1.3 beta - so it doesn't apply to the current release version (1.2.3 at time of answer).

My suggestion would be to add more RAM. My i7 machine stuttered with 8GB but after moving to 32GB it's much better. It probably helps alleviate any disk-related bottleneck. You can also record at 75% and upscale the picture afterwards.

Are you aware of the graphs and overlays included in Simcity 4? They'll let you see where pollution is heavy & crime is up. fix those and the land value goes up. Especially in areas where $$$ sims are living. Rich sims ($$$) are attracted to high land value areas and require $$$ industry/commerce jobs. So to increase your population of rich sims, work on maximising land value (education, crime and pollution seem to matter more than health and fire).

If you're quick enough, you can also demolish a station and build another over it. The new station will retain the details of the first and the vehicles will return when their orders next dictate it.

Have a look in the manager's office... Unless I'm thinking of the wrong club (likely).

@Arkive Yep, I've seen a couple.

You'll also notice that your Torchlight 2 uses grid-based movement across the terrain (try clicking at your characters feet to understand the boundary of the grids). It would be nice to compare the measurements above with this grid to work out whether the grid is based on 1m or 0.5m square plots.

Don't forget that like mining diamonds you should also use a pick enchanted with Fortune to maximise loot drop. That way you can get more than one drop per block mined.