Regarding saying it aloud—what is the source for the need for intention? When Boaz said to the harvesters, “The Lord be with you,” did he say it with intention or without? What exactly is the definition of intention? In the Hebrew Bible there are examples like this from everyday life. It doesn’t seem to me that there was any great intention there. There is certainly no intention to show disrespect. If Boaz says “The Lord be with you” as a greeting, then why can’t we say “Elohim” when we are discussing Him—a context where there is certainly no disrespect?

Why are you assuming that Boaz did not intend it? That begs the question.
Many halakhic decisors argue that mentioning God’s name outside the framework of prayer, a blessing, or Torah study is taking His name in vain. Therefore many are careful to say a name that is not sacred (a substitute term).
Beyond that, as I wrote, saying God’s name requires intention. One can discuss whether this is because of uttering it in vain or not. Some have written that this applies only in prayer, but in my view that is not reasonable. After all, in the straightforward sense this is not part of the laws of intention in prayer, but a rule about uttering God’s name.
From all this, it seems to me preferable to avoid saying it.