As I plan on doing some track events with my car, does the stock computer have any built-in cut offs (such as speed limiter) ?

 

Not that I'm aware of.

 

Other than the two rev limiters? Not that I know of.

 

there is a SLD (speed limiter) in japanese s2000's, but not in US. so your fine.
The only thing you need to do is make sure you run either one step colder sparkplugs or use 92-93 octane gas and reset the ECU before you track. The stock ECU is very sensitive to knocking, meaning, at the slightest knocking detection, it will pull timing like crazy to effectively robbing you of power. just keep that in mind.