Too busy to really think this out right now, but few mentioned rain jacket. Are you only going if the weather report is for no rain? TP - do not need- for one night use the wash with leaves method. Water filter - I would not take it in most the areas that I backpack. Obviously no-cook food eliminates stove and pots. Only take your hiking water bottle and finger food. One of those filter/squeeze bottle combinations might be nice, but is that technically two items? First aid kit? Meds? I once forgot my allergy pills and suffered greatly. I know some folks have meds that they HAVE to have. Poncho-that-doubles-for-tarp is probably a good item. Also, if you had a tarp, you could wrap it around you for a rain jacket. You get your rain jacket plus shelter all in one. No steaks needed either. I never use a compass - just map. I suppose if you use a GPS, that could be one item for maps, watch, etc. I like my trekking poles, but they are not a necessity. One night only- ditch the toothbrush and paste- in fact all personal gear. I left my ditty bag in the trunk of my car once on a 3-day trip and although it was not pleasant, it was not a deal breaker. Headlamp- I often do not take any artificial light on my regular trips - even 10 day trips.
You need very little, really. BUT, at some point you are leaving out stuff that may be needed in emergency. The risk goes up.