What is the general Buddhist consensus on catharsis? Is it fine if you are mindful while doing it? Or did the Buddha denounce such practices as revelling or exaggerating emotions to provide temporary relief? I find that simply being mindful while repressing emotions has a tendency towards leading to passive aggressiveness.

To be specific, I mean actions like systematically screaming to release anger, systematically feeling to release sorrow... etc. Purposely releasing these mindstates and going over the top instead of repressing them. 

What about other traditions aside from Therevada? Do they share a similar view towards catharsis, or is that not the case?
In my opinion, catharsis is a hindrance (non-meditaion) therefore not really related to Buddhism. Catharsis is a product of a deficiency in morality &amp; self-control (as explained in AN 10.61). In other words, catharsis is a secular matter rather than a Buddhist matter.

What is the nutriment for the five hindrances? It should be said: the three kinds of misconduct.
AN 10.61

This said, in MN 20, it is taught as one of five methods that sometimes a person must let a hindrance arise to overcome it. Often emotions are so strong, they must be endured and allowed to arise &amp; run their course.

If, while he is trying to forget those thoughts and is not giving attention to them, there still arise in him evil unwholesome thoughts connected with desire, with hate and with delusion, then he should give attention to stilling the thought-formation of those thoughts. When he gives attention to stilling the thought-formation of those thoughts, then any evil unwholesome thoughts connected with desire, with hate and with delusion are abandoned in him and subside. With the abandoning of them his mind becomes steadied internally, quieted, brought to singleness and concentrated. Just as a man walking fast might consider: ‘Why am I walking fast? What if I walk slowly?’ and he would walk slowly; then he might consider: ‘Why am I walking slowly? What if I stand?’ and he would stand; then he might consider: ‘Why am I standing? What if I sit?’ and he would sit; then he might consider: ‘Why am I sitting? What if I lie down?’ and he would lie down. By doing so he would substitute for each grosser posture (thought) one that was subtler. So too…when a bhikkhu gives attention to stilling the thought-formation of those thoughts…his mind becomes steadied internally, quieted, brought to singleness, and concentrated.