FWIW my best converting and best ROI keyword is the domain name, both with and without the .com part.
Which is another point that has been widely researched, whether one should bid on brand terms or not. We do it for all our accounts because tests have unequivocally shown an increase in profits.
In my opinion, no. Those who search on domains are a very small percentage
I bid on the company name and/or domain name regardless of whether or not there's keywords in it. Because the competition is bidding on it.