How many devices(controller) does BthPS3 and shibari/dshidmini support with one BT dongle?

Do i have to use 1 BT dongle for each controller or just 1 BT dongle for many?

As of time of writing you can not have multiple Bluetooth host radios active at the same time, that is a limitation of Windows so this applies to BthPS3 as well, you can only use one host radio. You can have multiple controller on that ofc.