It doesn't matter if the actual devices are not listed in the database, Yamaha & Samsung both have codes that have remained unchanged for decades. You will only be missing commands that are specific to newer equipment (i.e. Netflix button, Music cast button, etc.).

In particular, if you use code 515 under the TV codes. That has the Samsung codes for power 'ON' and 'OFF'. And the codes for HDMI inputs 1, 2, 3, and 4. Which should be all the codes you need.
Create your TV page, that is going to be hidden, and 6 buttons on it. Assign those commands to those buttons.

Then create your AV receiver page (that will be hidden) and start looking thru codes under Audio devices. 1660 has all your inputs and power commands. You'll need to go thru and test many others to find all the DSP (if you want discrete control over those - not necessary).

For your Radio device, use Audio code 1240. That has all your tuner codes you will need for the Yamaha.