1. Is an hour after eating a good time to lift weights?

2. Does doing for example dumbell presses exercises workout both the traps and deltoids?

im better at the nutritional side of things so Ill answer your first questions you want to lift when your body is able to deposit glycogen (muscle) this happens during the absorptive state of digestion and when your insulin levels are highest which is usually btwn 1 and 2hrs after eating your insulin levels start to level off and drop after 3 hrs and are lowest 4 to 5 hrs after you eat. This is also why you want to eat within and 1hr after your workout because Ideally your in your postabsoptive state (3-4hrs after you first ate) and since it unatural for our bodies to be carrying around a lot of muscle your body will use your muscle/glycogen stores as sources for liver gluconeogenesis. Just make sure your eating complex carbs not refined anything before and after or this will not work as efficiently