It doesn't have any side expansion slots like the A500 or internal HDD support. But there was an official (and I expect some third party) SCSI modules you could buy that plug into an internal expansion slot and add both internal and external SCSI for HDD and other devices. I also think someone made an internal IDE expansion more recently buy can't remember who.

There was also an official IR mouse released if you can't find one. Years ahead of wireless PC mice!

And, yes, you can control both the joystick and mouse from the IR controller, but it isn't great. best to just use that for audio CD control.

There was also a trackerball controller for mouse control. I see these and the official IR controller appear quite often for sale so buying a backup IR controller is easy if needed.

You are really lucky because the CDTV is the only Amiga I have still wanted and haven't ever owned. Just don't ever see them up up for sale over here.