Maine has lefty independents running all the time so yes, this helps the rats. LePage would have lost in 2010 under this system.
They use for primary. Not sure about general
Maine is certainly no conservative state, but I'm surprised an actual Peter Fitzgerald/Al D'Amato/Rick Santorum-type GOP candidate can't win statewide with 34% of the vote in such a scenario. "Independents" like Angus King agree with like 95% of the RAT party platform. In theory it should be easy for a conservative to win under the radar with the RAT & "Independent" campaigning on identical issues, identical platforms, and going after the exact same voters.