Great stuff on this forum, I’ll answer a bit at a time if that’s ok.
Firstly, (Emuna1 and Avira) The Alter Rebbe makes clear that even aveiros in thought cause someone to be a rasha. He says that in 12 and also in 11(the rasha perek).
But chazal said gimmel aveiros ain adam nitzol meihen bchol Yom. The Alter Rebbe specifies iyun Tefilla and says it’s not an issue to take someone out of beinoni unless he doesn’t refocus once he realizes he was distracted.
My point was that in the gimmel aveiros is included slanderous speech- hence my question about intention..