Bricks, Masonry, Asphalt and Concrete - Cement base for walkway

Hi,

I bought a book on pouring slabs but most of the info was geared towards patios. I want to make a 4 ft wide, 11 ft long flagstone/brick border walkway over cement and I wanted to clarify a few things.

1. The book recommends 5 inches of gravel under the slab. The heaviest thing this walkway will see is people+furniture (it leads to front door from sidewalk). Can I reduce this? Only reason I ask is to reduce depth I have to dig. Can I just place gravel and compact/spread it manually or do I have to have a power compactor? They did not go into detail on this in the book.

2. The book also recommends 3" thick slab. I have no problem with this but it is it necessary or can I put 2"?

3. Where do you normally want the final height to come out relative to the sod? About even with the top of cut lawn or at the top of sod..?

4. I want to use 1 1/2" thick brick to border the walkway. I'm assuming flagstone + cement will not be this thick. Do I have to put a second layer of cement down after the brick border is in to raise the bed so the flagstone ends up level with the brick? I saw in the book where they have a screed with a board attached to screed below the brick border.

5. I calculated just over a yard of concrete at 3" thick. Is this a DIY project? I have seen people buy concrete from the local yard with a little rented hopper/trailer.

6. Any idea if this is regulated by the city? I live in San Jose, CA.

Thanks

Bumping in hope of a response.