The buttons on a keypad are basically push buttons anyway,they are closed when you push the button then open when you let go.It depends what type of button you are thinking of using as some larger types bounce a lot more than buttons you find in a computer keyboard for instance,so your debounce routine needs to take that into account.
A google search should find info on lcds and no you dont need a pcb you can have flying leads coming off it if you want.