There are prior discussions where we add an Audio BT Transmitter to link up to headphones but we do that for a specific need (headphones.) No one I know would do this for speakers or mouse and keyboard.

For mouse and keyboard we look at something like the Logitech K400.

DO NOT BUY ANY BLUETOOTH DONGLE as these will not work on Smart TVs. Those are for computers such as Apple and Windows/Linux PCs.
Bob