If I build something that blocks a trade route the traders just stop in front of it. I have to clear and rebuild the trade route to fix it. If an enemy blocks a trader they stop and won't start moving again on their own after the impeding unit moves or is destroyed. Cities with both land and sea routes no longer have the issues I experienced before. Routes no longer seem to have problems when they cross many regions, though path finding across extreme distances is still problematic. Overall, trade feels much better, and these issues are manageable.
The enemy sighted notifications can very easily become overwhelming. I had to turn off effects sounds completely. Perhaps there is a solution where you could toggle off these warning for certain settlements, or maybe something more elegant.
Not really a bug, but it would be really nice if ranged units defaulted to skirmish stance, ships included.