Greg responds...

1. I had many stories planned. I'm not going to tell them here and now.
"The Director" was Robyn's boss -- Mr. Duval's primary nemesis, and a man after Xanatos' own heart. We did a five minute Leica Reel to try and sell the show. In the reel, the Director was voiced by William Devane, who would have also done the voice if we had gone to series.
2. We "only" had 78 episodes (and I only had 66). Not every thread was able to be serviced without the opportunity to tell more stories. Xanatos likes to acquire worthwhile things. He acquired the Eye of Odin for his collection before he even knew it had magical powers. The virus was a powerful weapon to add to his arsenal. Eventually, he would have found a use for it. Maybe he already knows what that use will be.
3. We had eight regulars, or eleven if you count Owen, Xanatos and Demona.
That doesn't count recurring characters like Fox, Matt or Morgan. Plus a huge cast of now-familiar faces. Not all the regulars got into every episode. (Even Goliath skipped out on four of them.) So by definition, Jason would only have been able to stop by occasionally. But he would have stopped by. I think Elisa still has feelings for him. She would have helped with his rehab, help him adjust to life in a wheelchair. He would have attempted to redeem his younger brother. Etc.
4. There are a lot of ifs to that question. If I had had the chance to do more GARGOYLES, but not TIMEDANCER or FUTURE TENSE, then I might have eventually moved some of my 2158 material up to the twentieth century. But, no, in my mind, Nokkar didn't resurface until 2158.
5. I think I've answered this one.
6. The other three would have left Avalon, with Oberon's permission... and a very specific purpose.