So uh, support main here - i generally play @ gold/plat/diamond levels. I disagree with most of what you said:
1.) It is very possible to have a positive kill-to-death ratio as a support main. I am rated favorably on the majority of my games. Do not be afraid to making plays, or taking kills as the support. Do everything in your power to get the kill. Always. In terms of ratio speak, the real wisdom here is: don't undervalue assists.
2.) This is a foolish behavior. If your ADC is terrible, then let him learn his lesson through death. Rushing to save someone who was caught out can lead to a string of deaths that create a MAJOR problem. You can throw entire games with this mindset. Be practical. If you cannot save someone, move on. Play smart.
3.) Positioning is critical in all roles, but ESPECIALLY as support because you are fragile. You must learn not to feed. Being a support does not excuse your deaths. If you die, you are playing poorly. Aim for 5 deaths or less.
4.) In general - everyone should be warding more. This is your only point that I agree with.