F stands for fractional, not float. So converting from integer to fractional.
I dont even think they are necessary, but as mentioned, i didnt test it myself.
Look a the names > conv/to f
The color of the inlets tell you the types(and ranges):
green = integer, whole numbers
blue = fractionals
yellow = boolean (on/off)
red = audio
Well sort of. The range of the midi out is -64 to 64, NOT 0-127. Look at the signs at the inlet, it usually gives you an indication of what signal you need to feed it. Since the inlet is blue(fractional) and there is a + and a - (plus/minus) the signal is bipolar > -64 to 64
So you could subtract 64 from the 0-127 to change the range from 0-127 to -64 to 64.
use a conv/unipolar2bipolar object to do the conversion. This is probably the simplest.
Just play around with it and get the simplest set up working and then start to add stuff. You will get there.