Joy,
Thank you for being part of the solution!
First, please understand that many of the people currently involved with HFY are new to the art, with only a few years at most of exposure, and many learn from students or grand students. If we were back in HK in 1953, and Leung Sheung had grand students, it would be difficult to expect them to answer detailed, precise questions, even if they did have backgrounds in other arts. Now add in the fact that most people here are English, not Cantonese, and we have to deal with transliteration and translation as well. "Mumbo jumbo", or "jibba jabba" is perhaps forgiveable under those circumstances! We're dealing not only with Gee sifu and his unique culture, but the "middleman" culture in between, which perhaps is causing some of the confusion.
Unfortunately, I don't have access to most of the source material sans "middleman", but I will answer as best as I can.
1. Space and time are relative. These are tools used to determine and achieve optimal results. Proper position in space (measured and aligned, then tested and ingrained through training) reduces the amount of time necessary to act. Similarly, it reduces the amount of options (space) and time the opponent has left to respond with. This is similar to the commonly seen proverb of "maximum results through minimum effort", but as with most things in HFY, there is a very detailed, precise, step-by-step method used to both teach and employ the concept.
2. By training for optimal results, even under the stress of combat, it increases the odds of acceptable results. If you train at 100%, perhaps you can achieve 80% under extreme conditions. If you only train with 80% (precision, etc.) maybe you'll only achieve 50% which could prove unacceptable. Time and Space is just a concept that gives a student a process they can undertake to help fine tune the best reflexes possible, and verify them for themselves, so they don't have to take any one person's opinion as the sum total of all reality. Others probably have other ways of doing the same, but perhaps not in this manner, or described in this way.
3. Chan can be either sudden or gradual, and while some maintain there is a strong connection between Chan and HFY, since this is a WCK forum, it is perhaps better to constrain ourselves to the martial aspects of HFY.
And yes, Joy and I have had some classic arguments which make some of the recent ones here look like love-ins. Glad that's in the past, and that this thread can help build better understandings for all.