I do not know of any USA based car makers buying carbon credits from Tesla.
While your first question is unknowable what we do know is Tesla has raised prices recently by $1,000 or more up to $10,000 per car and they're still booked into the future sales wise.
As to your last question again we have no way of knowing that but Tesla has stated that carbon credit sales are going away and they have not talked about going bankrupt because of it.
Today we all know talking about Tesla's carbon credit income is nothing more than a red herring. They are predicted to double sales or number of units made in 2022 to two million units.