When the pedal is depressed, it pulls a rope which runs through a pulley on the ceiling and back to the tensioning knob on the saw head, pulling the head of the saw up enough to clear the work so it can be advanced through the saw more quickly. With the foot pedal in use and the saw in continuous run mode, the cutting of multiple pieces can go very quickly indeed. I have seen several homemade base tables which make this operation easier, but neither have I ever found the one that came with my own saw to be inadequate. So stick with 14 tpi, but consider keeping some other sizes around for those special occasions. Generally, the more you pay for a blade the better it is.
Bimetal blades are great, but are expensive.
Carbon steel blades will see acceptable service for most smiths, but you may be a little happier with a slightly higher-priced premium blade that lasts a little longer and cuts a bit straighter. Yes, the sharper they are the straighter they seem to cut. One little trick some people swear by is to cut a piece of brass with a new blade before using it on steel. The theory is that it removes the burr and doubles the life of the blade. I'm giving it a try myself, but I can't claim these results.