Currently you can setup as many salesforce orgs as you would like as a source/target but you do not allow the same with VCS/Source control systems.

For example, I can only tie a single account to a single bit bucket. What if you have muiltiple bitbucket accounts that have different accesses to different repos - there is now way to do this in gearset.

You should expand the source control systems to be just like the salesforce orgs - you can configure and share as many as you would like for the same or different systems.