I am also currently trying to understand the TX path (on the LF side though) and I can tell that most of the time, the recommended schematics are full of unnecessary components (depending on what your application is), especially in RF.
About your analysis of the RX path, you got something wrong. C14, L5, C15 and C16 are for matching the SX1276 RFI port. You can use a VNA to mesaure the impedance of that port (make sure to put your calibration plane @ C15) and then using these footprints (double L network) to match the port to whatever reference impedance you need (usually 50ohms). U4 (?) and C17 are just shorts. C17 will be around 1nF which is a good RF short @ the operation frequencies of the chip. I would only put that capacitor since the 0 ohm resistor can have unwanted parasitic inductance (use thick film if you still want to put that 0 ohm for whatever reasons). Thats for RX.
TX is somehow a bit more complicated because it includes the Power Amplifiers options circuits. Have a look at this AN:
http://www.semtech.com/images/datasheet/rf_design_guidelines_semtech.pdf
Page 12 reveals the purpose of most of the components. Then, the way they describe to match the port can be used if you have the right equipment.
Do you have any tips since it has been 1 month this has been posted?
I'll work on that on my side and let you know if I find something.
A+
