Congrats Chris. That's a great neighborhood and I hope you do very well there. My initial reaction to you post is that it appears as though your strategy is to put below market finishes into your unit. I'd advise against doing that, for when the time comes to dispose of the property you don't want to have to put more work into it to bring it up to the neighborhood standard. Floors, kitchens, and bathrooms are some of the most important elements in house quality perception. Again this is just my two cents.
To really answer your questions let us know what your expected rent is going to be. We can better guide you on finishes as the expectations for $1/ft are much different than those at $2/ft.
1. Lots of folks use America's Floor Source but I've had luck from Floor and Decor.
2. Think about Ikea. Good cabinets. Good prices.
3. Can't help you on this one.
4. As you identified, the costs depend largely on your plumbing system in place, ie how much of your existing house do they have to rip up and put back together to run the electrical, plumbing, and venting. Without more context, I'd swag budget it between $10k-$20k.
