As I told you the only thing that will change is the SNR will be downgraded by an amount you pretty much for certain won't notice. One point you raise is up sampling.
There is NEVER an advantage to up sampling. A Wav. file will always carry the characteristics of the lowest sample rate it ever existed in. If you think about it, this has to be the logical conclusion. So up sampling does not harm, but brings ZERO benefit.
I do think you are stating to get the hang of it now.
All this assumes that you are working with non lossy codecs. All this is not to be confused by the ubiquitous use of lossy codecs in order to save bandwidth, especially for streaming.
These are codecs we are talking about. There are I'm sure others I have never heard of
- MP3
- AAC.
- ALAC.
- AIFF.
- WMA.
- Ogg Vorbis.
These codecs use psychological research to determine which bits can be thrown out, without people noticing. Although this sounds an awful idea, in practice the good codecs actually work very well. ALAC for instance is what Apple uses. MP3 is not that good, and I can usually detect it especially at the lower bit rates. AAC is a particularly good codec.
The there is the WAV, file which is the protocol in which the digital form of music is stored, edited, converted etc. Wav. files can be lossy or not, and encoded in pretty much any codec.
Then there are so called lossless codecs like like FLAC where there can be sent in code, but the information is there to fully restore the file to non lossy. So they use a code/encode system. FLAC is totally seamless. It reduces the transmission bit rate by just under 50%. It is totally seamless and undetectable to the listener.
The BPO have started using FLAC in their streams which are excellent.
Since this is all very complicated it is not surprising there is misunderstanding with false information on the NET abounding. Hopefully not here, but no guarantee. But there is usually a member to set us straight in our errors. What we pretty much do not like is the willfully ignorant, especially when peppered with any degree of arrogance or abuse. You on the other hand seem ready to get the hang of this. We recognize this is not easy subject matter and not always intuitive. We have to constantly remind ourselves to leave our old analog thinking at the door. For an old duffer like me this can be easier said then done at times.