Lee, I am liking the looks of that!! [8D] ...Still brainstorming as to why it's operating the way it is.[?]
Questions:
Are the blinkers on dimly even when you haven't signalled for blinkers? In other words are they on ALL the time or just after you select left or right or hazards? (I'm assuming No.)
When the blinkers were operating slow (before you added resistance) were they going completely off?
Have you tried a smaller resistor? (More like 10 or 15 ohms with an appropriate wattage... I think you still may not be drawing quite enough current to drain the capacitance from the relay.)
One other suggestion, you may think it's dumb but...
What do you think about putting your tail light integrator back in? Keep the signal blinkers you've got AND add in the integrator. You'd have to have your blinkers on the input side of the integrator so as the blinkers don't both go on when you hit the brakes... but the tail light bulb then being in the signaling circuit may solve your current (no pun intended)

problem.
...like I said, just a thought.