As I said in PM, this would be very hard to describe accurately, as it would require extensive knowledge of the hardware, drivers, engine code, game code etc. It would also be likely to vary widely between systems.
I had a long post here, but I realized I was just repeating what was more clearly written elsewhere. I suggest you get the unlagged source http://www.fileplanet.com/dl/dl.asp?/planetquake/alternatefire/unlagged-2.01-src.zip
(found on the unlagged website http://www.planetquake.com/alternatefire/ )
Go to the docs directory of the zip, and read network.html (note, this is not the unlagged FAQ)
That doesn’t describe everything you ask about, but gives a good, non-technical overview of what the game does. One slight correction is that cl_maxpackets controls the maximum rate client commands are sent to the server. Note that they are still only sent between frames, which will cause a bumpy effect in your lagometer if your cl_maxpackets do not evenly divide your fps (or they are not equal, and one or both do not come out to a whole number of ms.) How often snapshots arrive depend on snaps, rate, and sv_fps.
The biggest error in your post is not recognizing that client thinks (on the server) don’t run at sv_fps. Client commands are processed as they arrive.
Another error is that ping is round trip time, not one way time. Note that each one-way time is unlikely to be ping/2 since home connections tend to be asymmetric, and the packet sizes may not be equal. Also be aware that in game ping includes a certain amount of processing time on each end, which is one reason in game pings don’t match what external utilities show.