Oh and clearly need help with the giant TV we received as a generous gift!

Yes, we agree.
Oak flooring will be great.

Oak flooring would look nice. I would mount the TV above the fireplace.

OK so so far I am hearing oak flooring. I assume I try to match what I already have in the dining room. Do I take this all the way down the hall and then carpet for bedrooms? And then what about the stairs? I am so grateful for the advice!

And I am very open to any decorating help beyond my questions.

Yes, I would install the wood down the hall and carpet in the bedrooms, if you wish. In what area is your home? In a colder climate I would opt for the carpeted rooms; in warmer areas you could continue the wood into the rooms as well and use area rugs.

Agree with installing the tv above the fireplace and livening up the angled wall with a large piece of art or a gallery arrangement that continues down the stairs.

Yes, I would match the color and style of the wood floor that is already installed in the dining room. I hesitate to use wood on the stairs; it is fairly costly to do it correctly and does tend to scratch with kids and pets racing up and down. I think carpet would be a better choice there, financially and practically.