Hello,
It is nice to see so much progress 
Before moving on to adding more features, it is a good idea to spend some time fixing the crashes and bugs, and maybe also trying to use the XFS filesystem inside Haiku, either as a kernel add-on or using userlandfs. This will allow more extensive testing: having multiple applications running and accessing the filesystem in parallel, for example. It allows to go much further than what you can test with just the fs_shell.