The most effective techniques according to who? based upon what criteria? Was it influenced by the original thinker's build, their experience, their attempts to use certain techniques in certain circumstances, their own deficiencies?
Yes of course all of these things would have been influences in the beginning. It was based on the criteria of would work effectively when Judo grappling and Kyokushin striking with face punches were employed together, and what wouldnt be very effective.
It was tested and developed over many years where our founders students put their skills to the test against each other and against fighters of different styles from around the world.They also went to train with specialists from various styles to expand their understanding.
It also attracted experienced fighters from other backgrounds who brought their skills to the table thereby expanding our art.
It is a process which still continues today. A constant evaluation of the most effective means to overcome an opponent for each individual, according to their own natural strengths and preferences. There is no one method fits all approach. (which you seem to be advocating as superior?)
So you see a variety of "styles" within Kudo. Each fighter develops a certain style of his own based on his teachers experience and ability to help him, and his own experiences in sparring and competition.
I think this is perhaps the major difference in our philosophies. I see it as a process of constant evolution according to each individuals needs and goals.
You seem to be saying that if you feel the need to deviate from your original founders preferences, then its because you are at fault. His system is perfect.?
For example when I'm training Wing Chun with someone of a different build if certain techniques work for me but not them and others for them but not me are they all deficient techniques or is it that there is a difference in our individual ability and the specific environment?
If they work for someone, then probably the latter.
If during a fight / pressure testing I attempt to respond in a certain way and it goes horribly wrong does that mean that the response is flawed or that I chose the wrong response, or even chose the right response but hadn't trained hard enough or been taught well enough to make it work.
Yes possibly all of the above. Its up to you to figure that out and/or your teacher to help you realize which one it is.
In my experience (and it is only a personal view and not meant to insult anyone) development of many eclectic systems stems from lack of ability of the practitioner to put their art into practise under the circumstances presented. The practitioner then assigns fault to the system and seeks to fill a percieved gap by incorporating something else. Of course there is also trend following, when pressure point fighting was fashionable it suddenly appeared on an awful lot of syllabuses (should that be syllabi?), likewise escrima, and BJJ and so will the next fashion.