So I have been following some of the climate stuff trying to sort through all the "info" out there.Sea levels have risen about 8 inches since 1880.

or surveyors do the same survey and are off by 1 inch.. :)

Level the ground, add an inch of gravel then play legos tomake them fit neatly. no mortar no pins but plant appropriate above- trailing rosemary, and perennials for you climate.Where is this?

You would need to submit planning for this, get approved, and get two inspections for this from the county-wide health department.If the bathroom for this ADU was already in the basement (I assume it was, or you would have mentioned it, as the 4-inch branch drain for the toilet would have been far more difficult and expensive than the minimum 1 1/2 inch brain drain you need for a kitchen), you would have to worry about upgrading the egress practicalities as soon as that drain went in.

I have a crack running the length of the patio about 1/4 to 1/3 of an inch wide and 40 ft long.

Interest rates are starting to inch up squelching some of the demand and more inventory is coming to market with Spring temperatures kicking in.As Norman commented, we need more information about what you're looking for to narrow your search area.

If you’re near recycled concrete 1 inch with fines.  

Your main expenses might be sewer, water nearby is one thing, but you will need a minimum 3 inch line for the waste from toilet.

I expected to see the old 1/4 inch tile grout line indentations but nothing yet.

They're roughly 31 inches by 30, the screens are half as high - about 30 wide by 15 high.