Can wearing eyeglasses actually make your vision worse in the long run?

A balance. For reading, there is a natural decline in focusing ability throughout life that becomes more problematic between the mid-40's and early 50's. The eye is comfortable with focusing about half of its full ability, so using reading glasses that do part of the work while the eyes do the rest maintains a comfortable balance. Trying to force reading without help leads to more problems like eyestrain.
No. This is a classic "old wives tale". Glasses improve the vision but do not cause any change in the basic eye power which will end up where ever it is destined whether you wear glasses or not.
No. No, it may make you more dependent on the glasses to see near vision. But this is happening with age and hardening of the lens regardless of whether you wear glasses.