1) stock dogs, at least it seems to me that i have heard of those breeds being used for many different tasks
2) quieter on track than most "houndier" breeds, less range also. not as catchy as bulldog breeds, not really sure what you're asking for on this question....may be over my head

3) see above, and reverse it.lol
4) yes, at least in more recent history
5) no
6) depends on the timeline you're talking about. you go back far enough and
all breeds are related...