Having a tapered tube (even if it is pipe thread taper) is an all around bad idea; it makes having a plumb post relatively pointless. If you carelessly set the post out of plumb, you should bend it until it is plumb or start over. Setting below the frost line is part of the process.
The way we've done it for some FTA installations, there's no taper to deal with. The pipe gets cut off about a foot from one end before planting it with the cut end down. A standard floor flange is screwed onto the top threaded end, with another flange screwed onto the cut off stub. The two flanges are then bolted together using either flat washers as shims, or my preference, a double nut stack that allows the stub to be tweaked as needed with just a wrench and a level, similar to the same way we plumbed masts with anchor bolts set in concrete for the C-band dishes. Going below the frost line is a given, but particularly in the clay soils common in parts of the northeast, the pipe will still move around over time from the freeze/thaw cycles.
I used an 8' ground rod connected with #6 copper wire to the dish and connected to a grounding block on the coax from the dish. I ran the RG6 coax through 1/2" flexible plastic conduit.
With the addition of a #6 copper wire running back to the bonding point, this should meet code.
Almost all TV providers bill a month in advance. I can't say I've seen any bill in advance of installation as the installations are usually a fast turnaround.
