What you say is all very true.

The CGT we could be subjected to some time into the future will be offset by a fairly large capital loss incurred and on ATO record as a left-over from the 2008 GFC crash. That holds in perpetuity. So if we ever had to invoke it then the loss would be put to good use in that way at least.

Yes the floor area claimed used must be used exclusively for any business. In our case we have set up what was the garage of our house and it will never have a car in it. That space is 100% for our ebay use exclusively.