“If Nixon wouldn’t have resigned, would they have prosecuted him?”
If President Ford hadn’t pardoned him, Nixon would likely have been prosecuted. Democrats hated him as much as they hate Trump today and wanted to see him behind bars. Ford pardoned him to save the nation the legal spectacle the Democrats and their allies in the media were hoping to play out, culminating in photographs of Nixon behind bars. Ford’s pardon stopped this effort and he paid for doing what he thought was best for the nation by losing his election bid in 1976 to the virtually unknown (outside of Georgia) Jimmy Carter.
They wanted Nixon’s scalp since he worked with HUAC.
If Nixon was impeached would the Senate have convicted him?
I suggest not
Nixon was very popular and I think that the repubs would think twice about voting for a conviction