What I mean by "QI also as currency" is, mostly, being able to trade QI.

Dueling for QI, e.g. /duel 100 TC (dueling for 100 TC)
/duel 20 QI (dueling for 20 QI)

Paying for Orc Force, e.g. Costs 160 TC (IDK if real price, just an example)
Costs 15 QI

And then just being able to give away QI. I really don't see how this could be a problem, and why it isn't already implemented. Though, I can understand the creator(s) meant QI to be earned, but then why can you purchase it from the ToriShop?

You can already give away QI, for a price.

63kk per Qi.
Buying QI is 1kk each I think.

They're designed as TC-Sinks.

Yep, 1 mill per QI :P, why not just go and play 1 game?
But I still think it would be nice to duel for QI, that'd be sick.

Qi is a representation of experience. You can't bet your knowledge of math, or your ability to speak Spanish.
It simply doesn't make sense, and it won't be implemented.

Plus it would encourage farming ;o

Simply no.

You could duel Qi, but it must be above 500QI.

And how could you farm QI if nothing is earned, but simply transfered?
And if you try to transfer the QI, you must have over 500. Maybe even 1,000.

Qi is supposed to be a count of games played. It will not become a currency.