These bulbs are rated as 2700K temperature, on the warm side of the color spectrum (more yellow). Your 5000K preference is the cool side of the spectrum (more blue).
Make sure the sensor is rated for LED bulbs. If you put the bulb in and it flickers your light fixture cannot handle LED. You will need to replace the sensor which starts at around $9 or get a new fixture.
Not sure as it varies based on what you are purchasing. But do not buy as it will fail and then you are stuck with the product unless you want to pay more that the cost of the bulb to obtain your warranty replacement.
My fixtures are open so I have no idea. According to the internet, the LED bulb package should say if they can. Some are specially made for that and some are not.