Misc items are not totally devoid of use. There are certain quests which require misc "junk" items, including Conductors.
Various recipes also require these items. Notably, Tin Cans have use in a few quests (for one you need 100 pieces of junk metal... that's a lot of cans!) and in certain recipes.
Having a lot of empty bottles and Old World Blues can help you get Desert Survivalist. In fact, a lot of junk items have a lot of utility once you've fully upgraded the Sink in Old World Blues. (Potential spoilers if you haven't been to the OWB DLC yet, but see the Sink's Book Chute as an example)
Really, though, there are a lot of these misc items laying around, so selling a few of them isn't going to cause you a large issue. If you systematically collect all the things and sell them, you're going to end up in trouble, though.
In the long haul, the bigger problems are your carrying capacity and the amount of caps the merchants have. Most of these items are heavy and mostly worthless. Even if you only carry the light, valuable, useless vendor trash, you're probably going to have more value than you can reasonably sell, even at low Barter levels.