I don't think they're strictly necessary. The main Hellboy story can stand on its own. But if you have the time and inclination, the short stories can offer some interesting side adventures and character developments.
Not necessarily. It depends on your reading preferences and how much background and additional context you want for the main story.
It really varies. Some people find the short stories add depth and understanding to the Hellboy universe, while others can enjoy the main story without them. It's up to you and your interest in exploring more facets of the series.
Chapter 753, "Final Judgment", is the clearest early answer because it turns Shu Yan's situation into a concrete plot event. Early on, In the decade she had been with Fang Wenzhe, Shu Yan never thought.... By the end, But Shu Yan was simply too outstanding..
Chapter 826, "Deadlock", is the clearest early answer because the violence around Yu becomes final instead of hypothetical.
Chapter 855, "This is Made of Gold!", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. It opens with Sure enough, kids with sweet mouths get candy. and closes on This one little Pixiu can buy you a room full of toys!" Jiang Bufan:....
Chapter 696, "I Am a Very Narrow-Minded Person", is the clearest early answer because the buildup finally cashes out in a real clash. The chapter gives readers a real answer by opening on But she heard Jiang Li say, "Mom, you don't need to be anxious, I'm...
Chapter 627, "Definitely Not an Accident", is the clearest early answer because it turns Pei Ye's situation into a concrete plot event. Early on, He looked at the sinister smile lingering in Jiang Li's eyes, then at.... By the end, No one in this world was worthy of his sister!.
Chapter 710, "Handsome, Who Are You?", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter gives readers a real answer by opening on The man was wearing the white cotton attire of a beauty salon, the...
Chapter 703, "Slap Oneself", is the clearest early answer because it turns Bai Lu's situation into a concrete plot event. It opens with Wu Daoshan quietly raised his head to size up Zhao Lang, and sure... and closes on Young Master Gu was intending to back Jiang Li..
Chapter 733, "Those People from the Jiang Family Are More Stupid than the Next!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter gives readers a real answer by opening on Okay, Sister, you should go to sleep now.
Chapter 567, "Distant Nephew, Long Time No See", is the clearest early answer because it turns Gu Yu's situation into a concrete plot event. Early on, After separating from Jiang Li and the others, Team L headed in the....
Chapter 562, "So You Are Not First, But Last?!", is the clearest early answer because it turns Team's situation into a concrete plot event. The chapter turns that into something concrete by moving from After they finished preparing the fish, Guo Xing and Luo Xuan got...