'uses' is the number of time a condition/trigger can be called.
<option name="uses" value="4"/>
Means that the condition/trigger can only be call 4 times, it can be call 4 times in 1 turn, or take all game to make the 4 calls. After the 4th call, then the trigger can not be used any more for the rest of the game.
The 'switch' is a condition option. In my above example I created a condition called 'Lyttian_War_Switch' which contained '<option name="switch" value="true"/>'. So this condition is always true for any condition/trigger that uses it.
Then I changed the 'conditions' for Lyttian_War trigger and add a check for Lyttian_War_Switch:
<option name="conditions" value="Lyttian_War_Condition:Lyttian_War_Switch"/>
So the trigger will only fire when both conditions are true. With a chance of 6 or less out of 6 (always true, you will always get a 6 or less, when the highest value is 6) then the relationship between Rhodos and Mecedon will change to war. Then I changed the Lyttian_War_Switch condition to false. The next three lines are taken together:
<option name="players" value="Rhodos"/> <!-- not needed because the trigger is attached to this player --> <option name="playerAttachmentName" value="RulesAttachment" count="Lyttian_War_Switch"/> <!-- changing a player RulesAttachment name 'Lyttian_War_Switch' --> <option name="playerProperty" value="switch" count="false"/> <!-- changing the 'switch' value from true to false for what uses this condition -->
Hopes this helps what I was trying to say.
If we use switch on the condition, how many rolls when the trigger fires?
Again it is hard to understand what you are asking, the trigger will only roll once every time it fires. How may times will this trigger fire per turn is hard to say with out a 'when'.