Touche. I worked several years in airline ground ops, but I'm not a pilot. Perhaps you can educate me then.
Obstacles to your plan, as I see it:
-All eastbound flights would have to leave the US at dawn in order to make Europe by dusk, given 8-ish hours in the air and 5-ish hours of time zone change, depending on the cities.
Leaving the US at dawn would make it impossible for passengers connecting into the international hub city (the majority of the international passengers) to catch the international flight, since flights don't leave the "spoke" cities at 3am.
-The aircraft would have to overnight in Europe, since it would not be able to get back past Iceland before dark, thus reducing each aircraft to doing a one-way trip per day instead of the current round-trip per day.
Beyond these logistical issues, is it really acceptable to just take off and figure you'll "find a way around it" by sight? Is the plume small enough to fly around, or do you have to make sure you pass Iceland on the right side so you don't get stuck on the north/south side of the plume?
I'm not sure anyone's saying that it's impossible to fly A plane to or from Europe right now (after all, AF1 is planning to make the trip). But the obstacles involved for anything resembling normal airline operations seem quite high.
Back to your resume - how much experience do you have making an airline run smoothly?
The visual rules would only apply where there is a possibility of plume encounter. This means that the majority of the flight can in fact be done at night. The acceptable plume density an aircraft could safely fly through would need to be determined and an appropriate safety margin established. All doable with current technology.