I'm not 100% sure, but if I took an educated guess I would say this:
75 watt bulb would give off more light (but you are using more power, 75 watts as oppossed to 18 watts). There should be a number on the light bulb package, I think it's called lumes. The higher the number the brighter.
The 3 wire mounted control I'm guessing would be if you wanted to control the fan and light seperately from the switch and not the pull strings.
The remote is if you wanted to carry it around the room like on the bed or couch or something.
Typically, if you wanted to control the light and fan on seperate switches you would need 3 wire cable running from the switches to the fan. However if there is currently only 2 wire cable, I know there are some fan controls out there that will still let you do it.
In my brothers house he had fans with no switches when you walked into the room. You had to walk to the center of the room in the dark and pull the string. I installed a brain in the fan that was controlled by a wall mounted remote. Only thing bad is you have to change batteries. He didn't want to break any holes to run wiring.