No. It's still crap. First it does not solve many of mentioned issues (likely makes some of them worse). And it must introduce interface complications. (while instant bonus trade already has everything you talked about, with 0 additional interface). The point is that such risk free stuff is imbalanced, thus one way trade is best, and simplest, it even would simplify current interfaces as the need to display trade routes would be abolished.
Anyways I started looking in a code, and at least for human players it should be doable, so I'll be working on a patch, though for 2.5 version of freeciv, but it should come out quite soon anyways.
Again trade routes have basically 0 advantage when compared to instant income trade. And I have very very strong suspicion that they were made "to simplify micromanagement", but would say that, that comes at a great coast, and I would even doubt how much it solves that.
Also just now I though that with instant trade, some cities would be much more important, as there would be no arbitrary limitations (like 4 trade routes per city, which is totally arbitrary; also less arbitrary numbers is definitely a plus in my book), some cities would become much much more important and could truly be centers of trade. With all what that implies (most likely expect raids and similar).