I got home early tonight (7:00) and had time to work on my garage
door. Some folks (Ken Sterling & Others) gave me a bunch of
suggestions that I tried out:

1. The weather stripping wasn't the issue - there isn't any except
for the bottom of the door.
2. All rollers turn & all hinges look okay.
3. I disconnected the lever arm from the chain drive and it goes up
with more effort than I'd expect. Again, nothing seems to be
dragging/catching. The tracks are in place, aligned, etc. I'm
betting the springs are the issue.
4. The track that the chain drags the trolley along is greased up
really well.
5. The cable running from the base of the door to the springs has a
relative few snapped strands but not enough to pose any issue. I'd
chock it up to normal aging/use.

After monkeying with it for a little over half an hour, I'm pretty
sure it is the springs and will work on replacing all four. I'm going
to look for springs sufficient for a 400# door and take one with me in
order to compare. I'm going with the suggestions to:

a. Replace all four springs at once to avoid an imbalance.
b. Install the safety guide wires should the springs snap in the
future
c. Tension the springs by applying enough force on the wire to
stretch them 2" when the door is open.
d. If the pulleys are cheap, I may shotgun the fix and replace all 4
while I am at it.

Thank you all for your help & patience.

--George