What do you mean by 'common ground'? If you mean 'find words and meanings that you both agree on' then I agree, but there are some opponents that I find so morally repugnant that I have no desire to make peace with them.
As for avoiding logical fallacies - that depends on who you're talking to and the purpose of your discussion. There are times when a logical fallacy can be a useful way to frame an argument.
If someone's so morally repugnant to you, I have to wonder why you'd have any incentive to practice any kind of intellectual honesty with them, much less find common ground. This has more to do with any scenario where you want to have a productive, honest conversation. If that's your goal, it behooves you to open up by convincing your opponent that you have a shared goal or perspective, and build from there.
The second point you make is fair, but these "commandments" are ASSUMING that your intention is to demonstrate things logically, honestly, and consistently. If demonstrating a logical fallacy falls within the parameters of your argument, say for the purposes of demonstrating an example of a logical fallacy, or to lead your opponent in a certain direction in order to demonstrate a certain point, you haven't broken any of the commandments. You've only broken the third commandment if you stumble into a logical fallacy by mistake.
If you recognize that mistake and fail to correct it, you've also likely broken the fourth and fifth commandments as well, which is much worse than making an honest mistake.