As to your disadvantages:
1. I find CC to be perfectly comfortable and no more or less than my OWB rig (which I can also conceal).
2. Practice, practice, practice.
3. I carry a commander length 1911 everyday. 80% of the year I wear shorts and a tshirt.
4. Sweat has never made ANY of my guns rust. I am smart enough to wipe them down if I carry them and sweat a lot.
I find it funny you chose to respond to this portion of my response given the other points I made. Seems like you want to argue. I already said I am all for open carry if it is legal. But I do not find it advantageous in any way.