So I have the relatively common problem of non-uniform heating/cooling in my house and I'd like some input on how to make the best of the situation. I've put up with it for a couple years, but now, I'm at my breaking point.

Basics:
I have a 1600 sq ft, 15 year old, two story house with a single unit forced air HVAC system. I have a large foyer that provides a convenient route for my downstairs heat to escape upstairs. The Thermostat is located near a vent downstairs.

I'm mostly concerned with three areas.
  1. Livingroom Couch
  2. Upstairs Bedroom
  3. Thermostat


After twiddling with baffles, thermostat, and closing vents, this is about as good as I could do to regulate temperature. If I set the thermostat to 71 degrees the couch in the livingroom (20 feet away) is about 67 degrees with a bad draft, while the upstairs bedroom is about 78. I had a programmable thermostat that allowed me to be comfortable upstairs at night. But to be comfortable on the couch during the day, I'd have to set my thermostat to 76 or so... you don't even want to know about my heating bills.

Failed Solutions
These are the things I had to do to get even THAT amount of control.

1. Set the baffles at the furnace to full-on downstairs and as close to full-off upstairs as possible.

2. Closed all the vents near the thermostat. Honestly, I got to the point where I closed all the downstairs vents except the two above the windows near my couch. All this bought me was a lot of whistling from the other vents while still having a relatively anemic airflow out of the two couch vents - the last vents in the system.

Concerns

1. Of greatest concern is the lack of airflow out of the latter vents in my living room. I really don't think it's the fact that its colder by my couch, but that there's a draft generated by the cold windows because there's not enough hot air from the vents moving over them. I have PLENTY of airflow from the early vents when they're opened, but that airflow doesn't seem to make it down to the last vents even if I close all the early vents. We're only talking 8 downstairs vents here. It's not like I have a huge house. Can you get blockage in the ductwork? Is it just some function of amount of air pressure and the amount of ductwork it has to travel? I'm thinking of mounting a fan on one of those last vents to create a lower pressure exit and hoping to get more flow that way. Is that a good idea?

2. Another concern is the amount of heat that escapes to upstairs. During the day, I don't go upstairs, so I'd like to be able to "zone" the house manually, by controlling vents and baffles, to keep as much heat downstairs as possible. My foyer just opens up, no lip or anything, so I feel like all the downstairs heat just escapes upstairs. I was thinking maybe I could add a clear plastic "lip" around the foyer so there was at least a cushion of air along the downstairs ceiling that couldn't escape upstairs... maybe combine that with a ceiling fan to help circulate it. Would I see a noticeable improvement there? How deep should I make that lip? 2 inches? A foot?

3. What about something a simple as buying a space heater for the couch area? That would let me keep the thermostat around 69/70 during the day and be comfortable on the couch. The upstairs would still probably be in the 75-76 range if I did all the normal vent closing and baffling to keep the heat downstairs. What kind of electricity costs does running a localized space heater involve?