You should be able to keep your back muscle taught and not in a forward bend. This eliminates the strain. It is the ideal position for carrying the load of your torso. The pressure in your hands should be minimal. Yes 54 is small for you. You should be on a 56. I ride a 56 and I am 6' .5". My next bike is going to be a 58. I have had a Schwinn XL which run big. The top tube height was just a tad high for me. The simplest method to sizing is stand over the bike. If you are not in danger of a falsetto but can't go any higher you are good. This gives you high speed stabilization. Also the bars on a 54 are narrower. Having your hands point in gives you less stability at high speeds.