Re: Closer to the wind question
In order to sail closest to the wind, you have to generate the maximum possible speed, and the sailplan and sail trim must be balanced.
We can only guess, based on your description, but my guess is that the jib was trimmed too full. If the jib is too full, the boat can't point as close to the wind as it can if the jib is flatter. Because of the fuller shape of the jib, the bow is pulled off to leeward.
When you took the jib out of the equation, the boat lost speed, but, because the jib wasn't pulling the bow to leeward, it appeared that the boat was sailing closer to the wind. I don't think it was actually sailing closer to the wind, because the slower speed, when you furled the jib, meant that the keel wasn't generating as much lift, and the boat was undoubtedly drifting to leeward more.
My suggestion is to try trimming the jib a bit flatter,a but remember that there is a point where the jib can be too flat. You need to find that ideal sail trim that enables the boat to generate a combination of the best speed and the best pointing angle. You'll find that by experimentation and experience.