I'll answer here to the questions somehow related to the Gift Data Manager tool. As Slayer mentioned, we're not really focused on general Switch modding.
For Event injection purposes, yes. Other than the Homebrew Launcher itself of course.
Wonder records takes the date-time from the internal system unix time. Changing the date/time from system settings won't work. Read the FAQ 9
I won't give further support o instructions on using switch-time. Users will have to figure it out from themselves. I also don't know if it can be dangerous. I used it few times and I'm not banned, but I wouldn't necessarily recommend to use it.
Forged BCAT themselves will not be sent to the unmodded switch. You have to redeem gifts in the modded console and only then proceed with system transfer to the other console.
Basically just avoid any installation. Which involves NSP, XCI etc. And don't use cheat in online competitive games, such as Splatoon or Pokémon online matches. And avoid mismatching logs. If you connect emunand and then sysnand Nintendo would notice mismatching logs, even if you didn't do stuff I mentioned earlier.