The loose negative cable can definitely cause the problems your bike is having. FYI don't disconnect your battery until you've first removed the max-fuse.
Yes remove the maxi-fuse first then install the battery then reinstall the fuse.Too late, I disconnected the battery to see if it would take a charge. It did, likely fully charged by now. If I reconnect it to the bike, should I first pull the main fuse? Will this somehow reset things? Thoughts?