In some situations State law does allow you to use deadly force, even if there is no threat to life or limb.
RCW 9A.16.050
(2) In the actual resistance of an attempt to commit a felony upon the slayer, in his presence, or upon or in a dwelling, or other place of abode, in which he is.
Remember this is referring a felony
upon the slayer not property!
Again the issue of place of abode arises.
The place of abode is with in or upon the place of your dwelling (house, hotel room, RV if you living in it) not your yard.
The place of abode includes attached buildings, porch, or deck
I often hear people saying not to use deadly force unless there's an immediate threat to life or limb of yourself, or someone else in your presence.
This is sound advice.
Now, in my opinion, breaking and entering into property that is not yours is enough for me to feel that I am at immediate risk.
If someone breaks onto my property with myself, my wife and daughter, then I feel he has every intention to do what he has to do from not getting himself caught or killed, and I am not going to stand there and say "Excuse me sir, do you mean us harm? Or do you just want some stuff?"
Clarity on both of these statements are needed, when you state property are you talking about your abode ie house and attached structures? then yes this is a good statement if you are talking about an out building or on the property itself then this would not be a good statement.
If someone was posing a immediate threat to life or limb and are on your property then by all means protect yourself, be able to articulate the threat which can be addressed with elements of Ability, Opportunity, and Jeopardy.