1.I hate to sound like a nitpicker , but I found a comma missing in your third paragraph.
我很讨厌听起来好像是在挑剔。但是我发现你文章的第三段里少了一个逗号！
2.A nitpicker who obsesses over each dime is too tense to live with market risks.
对每一分钱都斤斤计较的人，由于过分敏感，无法承受市场风险。
3.The nitpicker who criticizes her is her best friend Laura.
唯一批评她的是她的好朋友劳拉。