can this be used outdoors or does it need to be protected from the weathre?

it is IP68 waterproof, absolutely safe to use in outdoor

can you set it so it only charges the load during daylight hours,, when the solar panel is working,,??

It will only charge when you have sunlight on the solar panel 
 

What kind of light ( or bulb ) can I use?

any thing that is 12 volt 
 

does the controller have a reversing diode?

The controller will not drain power from the batteries when it is turned off. 
 

Want to use as a night light only. How is it set to charge battery during the day and turn on at dusk?

The controller will charge the batteries during the day automatically. No problem. You can use the panel as a light activated switch by using mode 2 or 3 of the light function of the controller. Or you can Leave the light timer on the controller on mode 1, 24hr so that power to the light is always available. Connect the power out of the controller to a 12 V DC dusk/dawn switch mounted so that it has visibility to daylight. From that switch wire the light. Use this method if the light you want to control is inside. The dusk/dawn switch is about $10-15. If the light is outside get a light with the dusk/dawn switch built in and you can direct wire to the controller using mode .

Will this recharge my batteries while I am camping?

yes, it will