‘...with someone who makes up their own rules and definitions as they go along...’
I think you are projecting your actions on others.
ID is not science of any kind, so it has to pretend. So far, junk science is about as high as its pretensions and aspirations have been. If it had been trying to be a real science it would not be pushed largely by a PR campaign by a religiously-funded "think" tank, the Discovery Institute. Rather, it would be doing research and other scientific endeavors and trying to get into respected peer-reviewed science journals.
I do not wish to debate Evolution with someone who makes up their own rules and definitions as they go along, so as to handicap their opponent.
Science works under a pretty-much fixed set of definitions, and these do not change at a whim. I have a good list of these definitions on my FR home page. I did not make them up; some are from respected websites such as CalTech.
What does change as one goes along is the definitions used by creationists. For example, theory, as used by scientists, becomes "theory" (a wild guess) when used by creationists. They do this to imply (dishonestly) that the theory of evolution is not real science but is just "a theory."
Look at the transcript of the Dover trial and note Behe's definition of theory under cross examination. He had to admit under oath that his definition of theory (deliberately made as vague as possible so that ID qualifies) also includes astrology!
I am afraid what "handicaps our opponents" is their inability to do science rather than any changes in definitions on the part of science. Science refuses to change its methods and definitions to include religion and other non-scientific beliefs, and this is a pretty large handicap for those pushing religion. Hence, their resort to dishonesty (“cdesign proponentsists" for example).
But why is there such an emphasis on pretending to do science on the part of IDers? Because they are seeking the respectability of science without having to do the work (that's kind of like buying your Ph.D. from a diploma mill for $30). And they are seeking scientific respectability to get back into the classrooms. Creationism and creation "science" have been removed from sciences classes by U.S. Supreme Court decisions, so some way had to be found to sneak religion back in. "Hey, lets pretend to be science! We can get some creationists elected to school boards and they can help us sneak this one through!") This little trick hasn't been ruled on yet by the U.S. Supreme Court, but it was ruled on by a Federal District Court (Dover). ID was determined to be religion in disguise.
That's why ID has a hard time being taken seriously by scientists. Its religion, not science!