Yeah your suppose to stagger the spacing

Everything looks great, I just did my basement about a year and a half ago really glad I did. Do you know what u are doing for floors? if u get a chance do you think u could sketch a blue print it's a little hard to tell layout from pics.

Different areas have different rules usually walkout you can add Sqft to listing even if you can't the agent will list liveable above ground space the add a comment like bonus sqft in basement. In the end if done right you will add value if you sell.

Are you not doing anything with the floor?

Ok concerning tiling over Concrete, one in a basement you should never use a solid wood subfloor whether it be plywood, Osb or true hard wood floors this is because of moisture from the ground through Concrete u can you bamboo and engineered because they breath and absorb less moisture. As far as the floor moving Concrete is not going to expand and contract to any significant degree it could settle or Crack but in the basement the Floor is not exposed to the elements or and true weight like a driveway I would not hesitate to tile straight to the floor, actual stone might be better since it will breath better then porcelain. Shit does happen but very more the likely you will be fine if needed I can post pics of my engineered Brazilian cheery floor and marble floor tile I did in my basement 2 years ago.

PS if you are actually going the bamboo engineered route there are a few more precautions to take can elaborate if need be.