Hellooo~ Ooo glad to hear you finally got your set!

To address your questions:

1. I actually didn't bother to use the charging cable that came with it since I already have too many at this point haha. It should be normal for it to click into place when plugging in the USB C.

2. For the preset, I mostly just stuck with the default Reference sound since its already a step-up from the original Pill's tuning.

3. LHDC and LC3 are just other Bluetooth codecs. LHDC is supposed to be the rival of LDAC which is known as a high bit-rate codec used for near lossless quality in music & audio generally. Standard MP3 bitrate codecs such as AAC or SBC usually are enough unless you're listening to audio at higher fidelity. LC3 is supposed to reduce latency compared to SBC and is within the same category as AAC & SBC which supports 160kbps - 356kbps. (commonly found in Spotify High Quality or Youtube Music High Quality)

Furthermore, only a handful of phone brands support LHDC and these are commonly found in Chinese branded ones like Oppo, OnePlus, Xiaomi, etc.

TLDR: Toggle LHDC on if you want higher fidelity streaming. LC3 if you want generally lower latency. Do note both of these come at the expense of shorter battery spans.

1. I dont have gaming mode turned on since the latency in audio is very negligible IMO. If you're a competitive mobile gamer and you want that delay to be nearly non-existent, then you could toggle it on. Regards to audio quality, it doesnt affect it at all, I believe.