F,
The pogo pins are primarily used with the Kameleons. They (the remotes) have pads; no pins, nor lands to solder pins in and therefore require a contact such as a pogo pin to be held to them while transferring the data. The 2116 has pins already installed, so you will not need the pogo pin adapter for it.
For some other remotes that do not have the pins already installed, the pogo pin adapter may be useful, but for most of these it is necessary to open the case and install an EEPROM anyway. If you can solder in an EEPROM you can install pins nearly with your eyes closed, so I would think most would do it while they are in there.

The battery retainer is also used with the Kameleon remotes to hold the batteries in place during transfer. Not necessary with the 2116.

The USB interface sounds like a reasonable choice.
Jim