I remember reading about taking pictures of animals. They say the best way to frame an animal is to give empty space in the direction it is looking, it gives a sense of movement and energy etc, doesn't block the animal in a box so to speak. So if you have the original shots, it might be worth adding/leaving some negative space in the pic to give a better impact.
I like your blah mate.
The f stop is the ratio of size of the aperture diameter and focal length. On the less expensive zooms ie Nikon 70-300mm you have a maximum aperture of f4.5 at 70mm and f5.6 at 300mm.
More expensive zooms such as the 70-200mm f2.8 have a maximum aperture of f2.8 throughout the focal range. This requires a lot more glass to achieve and, therefore, more weight and more money. This would be termed a fast lens, and you can rest assured that the light they let in gives a lovely bright view finder.
I use a 50mm f1.4 which will let in four times as much light as a standard f2.8, making it fantastic for indoor photography of the kids without having to use a flash gun.