While it's clear that cars with a Constant effect still apply while they have a focus, I didn't see anything that stated whether or not exhausted cards could use other abilities (interrupts, actions, etc.).

Can exhausted cards use printed abilities that do not require gaining focus?

If so, if someone could point out where this is stated in the rules, that would be cool.

Thanks!

The way i've read it is that the card abilities are always available UNLESS they say that you need to focus a card to use it.  If you don't need to focus to use an effect then I see no reason why it can't be used.  In the same way as the objective IN YOU MUST GO lets you reduce the cost of the first enhancement by 1.  The objective isn't EITHER use the ability or use it for a resource, it is both.

The relevant section of the rules to answer your question can be found on pg 27:

"Exhausted
A card that is exhausted (i.e. has one or more focus
tokens on it) cannot be focused to pay for card effects,
cannot focus to strike, and cannot generate resources.
However, other card abilities of an exhausted card
may still be triggered, and its constant effects (if any)
are still active, as long as such abilities do not require
the card to focus, to be ready, or are not otherwise
prohibited by the card text."

Perfect. Thanks!