Yes it could. But like Kayaker said, they were captured using a full frame 1D III camera and of course Bryan's skill level. The full frame camera is going to give an increase in image quality. Whether the lens will or not, you can go to the review tools on this site and compare the ISO charts of each lens to determine which one you think does better.
Yes in my opinion hoods and filters are imperative. Hoods keep stray light out, if you want the best quality you can get you should use it. Basic filters just protect your investment. Neuro gave you a description of several different filters, which if you are just starting out if you try and understand all the different types you are going to get overwhelmed. Things like polarizer’s and neutral density filters will help you do certain tasks with your camera. A basic filter is just clear glass that protects your front lens, some people use them and some do not. Personally I keep one on my lens in case it gets hit, if I want really good IQ on a particular subject I will take it off.
As for weather sealing of your lens with a filter, I have to say people talk about this all the time but for the most part I almost never get my gear in a situation where it is an issue. If you want to take pictures in the rain, off a boat, in a rain forest take in to consideration. If you’re like some of you guard your gear like it is a baby and it will never get tested.
You still didn't provide a budget in your response, not that were being nosey but it would help everyone give you recommendations if they knew how much you were going to lay out. Keep in mind when we can't buy new gear for ourselves, we live vicariously through others helping them spend their money....
Good Luck