Our builder in South Carolina installed the water supply shut-off in a recessed pit in our lawn that must be turned off with a city-type water tool. There is no main water shut-off inside our homes... is this legal according to IPC? Also all of my other homes had overflows in all the sinks but there are none used here... is this legal according to IPC?

Your home obviously had to be permitted and inspected so it must be legal there for the shut off to be located in the ground. If you wish to add a shut off inside your home go right ahead and have a plumber do it.

As for the drain holes in the sinks - some sinks nowadays are made with no drain holes. It's usually the cheaper models that have no drain holes. If you want drain holes change out the sinks for new sinks that do have the drain holes.

Both situations are obviously permitted or the building inspectors would have flunked the shut off valve and the no drain holes in the sinks.

Since I work over 20 years under UPC, I am not sure about IPC. But, I cannot imagine house w/o main shut off valve at the house. Where will you turn water off if you want to replace washer in shower valve ? Or if you have pressure leak ? Or in case of an emergency ? Here, shut off valves are required by Code. Some Cities in my area, like City of Santa Monica, will fine you $500.00 if they catch you turning water off in access box at the meter. I would suggest that you install one ASAP. No matter what plumber will charge you - it will be lot cheaper than dealing with possible water damage to your house caused by absence of such a valve...