1. Gold is not unheard of in cable. Xindak, a china company had it when I was young, not sure if they still do. More applicable for us might be the murdorf gold/silver with 1% of gold. It is available locally, but I am not sure if it will be too stiff/bouncy for portable audio application. I think it is used as wires more hookup inside your equipments.
2. The below is what I found out with interconnect, so maybe iem cable might differ, but I believe it shouldn't.
Pure silver is not always brighter. It can be better or worse than copper wire, depending on what you are comparing with and type. 1xrun of Silver+ 1x run of copper can be better or worse than just pure silver or just pure copper, as in the sound might be muddy and veiled. Reaon? I don't know, just experienced it. The 1x run of silver and 1xrun of copper was recommended at the shop, but after some trial and error plus a lot of time wasted to braid and unbraid, I found that if I only have the copper, it was good. If I only have the silver, it sounded even better. Yet if I have both, it wasn't in-between, but worse than having just either of them. For me, the difference between the silver and copper is more of airiness and the imaging. Other than that, I honestly think that I can live with either of them. If I didn't listen to one before the other, I might not be able to 100% tell which is which. Both cable were the 7n teflon sleeved from artaudio at chinatown there, so I assume quality should be the same. Braiding for the test was just simple braiding like how kimble do their pbj, tonik, etc. No cotton or other fancy material or sleeve or anything.
Same goes for silver plated. Silver plated cable of lower quality can be even brighter than pure silver solid core. Reason? I honestly don't know, but just had the issue.
For me i think the tf10 lacks bass? Too much on the highs but i like it <3
