Max Automatic HP
 

2000 Honda Civic EX D16Y8

Any idea as to the maximum power the automatic transmission can handle?

Probably nothing much more than stock. They are known to fail once extra power is being added.

Bolt ons are fine, but once you go deeper than those, I wouldn't trust it.

Planning on a cat-back exhaust and short ram air intake.
Was thinking on a Level 1 Bisimoto cam, adds 10% power over stock.
That would be the extent of engine mods.

Would adding a lager trans cooler help keep from failure?

I wouldn't suggest a cam. That requires tuning, good luck finding someone in the area to tune an AT, and correctly at that.