Decorating and Design - wall between breakfast room and tv room

TV room has floor-to-cieling fireplace. Breakfast room can be accessed via a large opening in the wall (bigger than a standard door). Breakfast room is fully "attached" to the kitchen. I want to break down the wall between the TV room and the breakfast room but have questions about the room transition - should the flooring match or should is it more sensible to devide it somehow?

To knock down a wall will require an assessment by a structural engineer to determine if it is loadbearing. If it is, then he will explain the need for compensating for the lack of support if you knock down the wall. This is usually done with headers. The engineer will likely advise on the number and size of headers required. Once you have your plan in hand, you have to get it approved by the local building inspector. If approved, you will be issued a building permit. Any changes to structure require a permit. Do get a permit. At time of sale, unpermitted work may have to be torn out and returned to the way it was. Too, you can get stuck with some hefty fines.

You will never get an exact match with the wood flooring in new and old area. But, you can install the same species and have both areas sanded and finished to make them look very much alike.

Headers may or not be a solution because they must be supported by columns. Of course, columns must be calculated by an engineer

Regarding the floor, if you have 2 floor with different materials try to use a neutral floor transition strip. You didn't describe the materials of your floor, but you can consider different options like wood, granite, etc