What exactly does 差不多先生 mean? I've been trying to study the song 差不多先生 and am having difficulty  understanding all of the uses of 差不多. 

Also if anyone is feeling super inspired, I'd love to have a full translation of the song. A good place to put it would be on Lyrics Translate.
差不多 literally means nearly, just about, or almost.

差不多先生 means the person pertains to the phrase 差不多 a lot, indicating his life style, loose, careless, etc.