We have ways of dealing with 0 or sub zero quantity on items using backorder but it puts our customers off when they see an out of stock label.
I can put the whole catalog back in stock using the admin backend of course but everytime I upload stock levels and prices many items again appear out of stock.
Worse, I do not know if magento has a cron job to put more things out of stock as it finds them with zero levels.
I have tried obvious things like set min quantity for in stock to -100000 but it would not accept.
I could quite easily write a cron job to put everything in stock every 5 mins but that seems wrong. There must be a way to disable this without turning off stock management.