With your original pictures - I agree with larger rug. But I don't agree with comments suggesting the rooms are monochromatic. They are lively indeed. I think you are just missing some accessories! Art work on the empty walls - even just a single large dramatic piece is in order. In the bedroom on the white wall, in the living space behind the sofa, in the greenish bedroom behind the two beds. Those are instant areas where you can improve. But I think your spaces are lovely and well put together. Also I agree with the comment about table lamps - some of those would really add something, and your coffee table looks so empty - maybe just one gorgeous bowl, or stack some books. These rooms are 90% done in my opinions, just need a few finishing touches. Some of my rooms come out like this because the clients are not willing to pay for those last few finish items or feel they can do that part themselves...

Mohammad. I understand your program. You may be lost in the details at the moment. Please do follow and trust the advice given here by all these people. You are about to embark on a reasonably expensive journey. Get professional help with someone who you can sit down at a table and brainstorm with them your ideas and intentions. There are Architects and there are professional building designers who are members of the American Institute of Building Design (AIBD) who are well versed in projects such as yours. I personally love a design challenge. After 38 years designing homes and special use buildings I enjoy this type of challenge the most. I am in Ohio and may not be close to where you are but I am sure with a little investigation you will find the best design professional for you.

It depends, it could cost anywhere between $20- 55 Per SF. You have 276 SF you can do the math and get a general idea.

I am assuming you haven't finalised your wall colours and colours of any other fixed elements. In case you have finalised your color scheme you would need to see which of these colours blend well or complement with that scheme. Assuming none of this info is available, then you could look at the neutrals which go with all colours. The white tile and the 2 colours at the end would be preferable. If you want color on the floor as well as drama, you can choose from the 2nd options from both sides or even the 1st from left.