No. Or yes: don’t change .items. If you (have to) do often, you should revisit your concepts.
It’s not required in normal operations. So there’s also no need to handle this in rules.
Well. What you are lacking is an overall programming concept.
The underlying problem cannot be handled locally in a rule.
A good concept is to
a) test for the state of any
item.state before you use it
If it’s wrong, log this information and appropriately proceed in your rule (that might mean “return” but you could for example also work with a constant default value or action).
b) properly initialize all items on system startup.
It’s good practice to write an “initialization” rule that validates all items (i.e. that they are not NULL and in range of reasonable values) and if they’re not ok, initializes them to a default value.
This rule you can run on system startup or whenever things have gone wrong or when there is a need to reset the great state machine.
You may also divide that into multiple smaller initialization rules so you can re-initialize parts or in stages and a single run does not affect everything.