you can sell the same name to
Small company for $5,000
Medium company for $50,000
Big company for $500,000
So the answers to all your 4 questions is not applicable
That appraisal seems like an anomaly. This happened because the word "fiold" very closely resembles the word "field".
Based on our testing, majority of appraisals are in the right ballpark. However, as you discovered there will always be anomalies as automated tools are never perfect. So you should still use your personal judgement.
The tool is intended to help sellers get a rough idea of the price. But ultimately it's up to sellers to decide how to price their domains based on their individual goals. Some sellers price them low to get a quick sale, others shoot for the moon by pricing them high, etc. There's no right or wrong strategy.
As @johnn pointed out, different buyers may also pay different prices based on how badly they want the name. This is why Voice.com sold for $30m while Fly.com sold for 10X less. So it's all about what makes you happy at the end of day (risk vs reward).