When we enter Israel, your passport is usually not stamped. You'll be given an entry ticket- and you'll want to keep that, not throw it away. So a paper clip in your passport might add an extra bit of security.
Why carry a plastic bag (or 3?)? For your washcloth when we change hotels, or your shoes, or dirty laundry or? It weighs almost nothing, but can come in handy in so many ways.