Brent, this seems to be a very ambitious undertaking. Those look like some big keywords that sound somewhat competitive. Here is what I would recommend for your questions:
1. Based on your goals, I would target the photography words as opposed to the photographer words. You'll probably just as easily rank for both if you have one, but still, someone looking for a photographer wants to see a small sample, then some contact information and pricing packages. Sounds like you just want the casual passerby to stop and stay a while. So I would focus on photography.
Your question about which terms to target is all of them! Make your home page photo blog or photography blog. Then make a category for each keyword you want to target, black and white, abstract, etc. Get each category page to rank for its keyword. Then you don't just pick one, you can do it all.
2. Photography over photographer(s)
3. Not enough keywords to focus on. A quick search for photography and you'll see a lot of different types of searches, from religious to nature to animals to objects. People look for all kinds. I would find all the different types people search for (That you actually do) and then create a category for each one so that you can upload your photos into each category and get that category page ranking for that particular term.
These are bigger keywords, but one key to SEO is deep links. Don't just link to your home page for one keyword. Get links to all your pages for all your keywords. This is why you should have a robust keyword list to start as you have already. You're on the right path.