How important do you consider group dialogue to be in understanding the more subtle points of Krishnamurti's message?

Dialogue was a favourite word of K - but, as he would say himself, the word is not the thing. Dialogue, if it is to work, must be a coming together of people who are completely, inwardly free from their conditioning in order to inquire.
Unlike a discussion, or a debate, dialogue attempts to go beyond the workings of thought. Watch the K videos and you will "see" dialogue in action. K never, ever, gets bogged down in thought or intellectual concepts. See for yourself. Pay attention. Listen deeply and you will discover what dialogue is and therefore come upon true understanding which is something entirely
different and new.

Can dialogue - in the sense of sincere inquiry - be organized or can it only come about spontaneously, unprompted?

Why do you want to label something "organized" or
"spontaneous"? Meet together in friendship, and
with real affection and see what happens.

Has coming into contact with Krishnamurti and his teachings had any perceptible effect on your life and/or relationships?

Fifty years ago, someone handed me a book written by
J. Krishnamurti. I was off to University, and his views didn't fit in to my "life plan". Over the next
fifty years K never let me go. In all the ups and downs of life, the successes and failures, he was always there like an eternal spring of fresh water. His influence on my life has been enormous. Even though I attained degrees in philosophy, psychology and education I was always aware, always listening to him. His teachings were beyond all the knowledge that I accumulated in a lifetime. Beyond the mere personality of K stands the most magnificent, timeless insights ever given to human beings.

What future do you foresee for Krishnamurti's works? Do you think they will grow in importance or will they just gradually die away?

I do not think these questions are important. What is important is whether or not human beings will listen,
respond, and change.

While there are human beings prepared to live the teachings there is no such thing as that "which
will gradually die away".

Do you think it is possible to make Krishnamurti more "practicable" than what he himself seems to have allowed for?

What do you mean by "practicable"? Do you mean you
want books telling you "how" to do something?

I am aware that many people find K obscure, at times.
Those who find that to be true, are usually trying to get something which "thought agrees with" or which "thought itself has created". Try going beyond "thinking" and "thought"...see what happens!

Do you ever feel that you have been conditioned by Krishnamurti's teachings?

No. To merely repeat what K has said, or shown us, is as futile as trying to package sunlight.

Which doesn't mean that sunlight doesn't have its place. It can provide illumination, but ultimately that will be fruitless if a human being does not use it to see for himself or herself what it means to live,
to be related, to love and to die.