In my opinion, an ideal discussion forum is that where the members can air their opinions sans bias without fear franly.. If there is a truth in the other member's view, with magnanimity one should appreciate and accept wholeheartedly.

In my opinion the members should post when they have something worthwhile to say and not only for filling up a slot. I would never reply to any post until I am addressed to or a point not said before by any other member. Merely saying yes to everyone does not solve the purpose of a discussion.

Discussion involves exchange of meaningful ideas on a particular topic. An issue is viewed under different perspectives and it helps us to gain deeper understanding about an issue.  Here, everyone has the freedom of expression, provided it does not hurt other’s personal sentiments. The persons who exchange ideas cannot come into a conclusion about the discussion. The audience or those who listen are the real adjudicators. 

An ideal discussion forum , in which every opinion added by the member should pave the way to knowledge to the members. In this process there may be differences with regards to the opinions of the participant members. They should be treated as mere opinion of that particular member. by all means personal attacks should be avoided to keep the sanctity of the forum.

In my opinion, an ideal discussion is exchange of views. Everyone is entitled to their opinion and need not accept each other's views. A discussion should surely be enriching . In virtual sites, many a times we tend to read too much between the lines. Comments should be therefore direct. Even if one gets entangled in heated discussion, one has to know where to draw the line to maintain a cordial relationship in the forum. Unnecessary comments of course are most unwanted.   

As far as comments are concerned, they should be lucid. Sometimes a bit of humor is alright, but such humorous comments should be linked with the content of the post. There should not be cryptic, mysterious and obscure .comments.

I love to be enlightened,informed and mischievously

controversial to draw the best out of my knowledgeable friends and the worst out of me! And if it is packaged in commanding wisdom and sparkling wit ,it is a generous bonus! Obviously mutual respect,dignity and openness make any discussion a truly stimulating and memorable experience.

I feel that a good discussion is one where members have freely aired their views on the subject being discussed and have contributed to the discussion.I will not say positive or negative because interpretations would be different to each member and it is difficult to draw the line! Sometimes the topic might be such that it might invite some controversial responses which should be taken by others in the right spirit. We are all adults here and can handle things , if not there are moderators to intervene and steer the discussion on its right track! Repetetive posts and ideas should be avoided  ..A little bit of humor and wit is definitely welcome since we are not on a college campus !

All other other things you said are mostly being followed. The main problem is with those members who drag on, saying the same thing again and again and insist on making others contribute to their opinions. These members are mere point hunters. This type has to be taken care of by the moderators.

An ideal discussion means free and frank expression of views,  responding to others' views,  flexibility and restricting to scope of the point at issue.  Flexibility is significant. If you are so rigid that yo cannot change your view in any circumstances, any discussion will be futile.