My writers’ group was critiquing my private eye short story and several people criticized it because the PI was not hardboiled. I’ll put it to this group.
Does every private eye need to be hardboiled?
Agents can certainly help with foreign-language sales (though there's not usually much money in that) although some small presses are taking over the agent's role by buying worldwide rights and then going to places like the Frankfurt Book Fair and the London Book Fair.
Well, if you want a publisher, you'd better have an agent. They handle contract negotiations, know who's looking for what, sell your subsidiary rights for you, handle tax forms, and do all sorts of other things. If you don't have an agent and you get a contract offer, you need an attorney familiar with book contracts. Many authors are very happy with their agents. I just had a bad experience with that one novel.
I write two continuing crime novel characters, one a PI, another who keeps running into trouble. After 33 books, I've learned a thing or two. One is that the world of crime and those in it is hard, mean and horrible. My two guys are tough as coinstruction I-beams.
Who is Baylor Rumble?
Personally, I would think that the only quality a (fictional) private eye really needs is to be in over his head, thus making sure he'll have plenty of trouble to get out of in interesting ways. Degree of hardness in boiling simply varies what level of peril will scare him (or her). When you bear in mind that the vast majority of cases real gumshoes take on involve little or no serious threat of violence or major criminal activity, it's easy to imagine somebody not very brave or tough, but suitably sly and wily, doing this job perfectly plausibly, and running into more than he bargained for on some trivial missing person or cheating spouse case.
I find that scenario much more interesting than the likes of Mike Hammer, who wouldn't feel seriously threatened unless he was up against - ooh, I dunno - the Third Reich? Also, it's interesting that in Robert Aldritch's superb film of Kiss Me, Deadly, Hammer is portrayed as the repellent psychopathic bully such a person would in fact be, rather than the awesome hero Mickey Spillane obviously thought he was (he even played Hammer himself in the film of I, The Jury). As for private detectives who also happen to be vampires, werewolves, or otherwise equipped with vast superpowers and near-immortality, who or what can possibly be a serious threat to them - the Archangel Gabriel, perhaps?
As a rule of thumb, if there's no sense that the protagonist might not get out of this one (even though we know he will because if he doesn't, the rest of the book will be kinda dull), then he's too hard-boiled for whatever plot he's in, unless it's just an über-macho fantasy aimed at very childish men who aren't too bright. To me, one of the hallmarks of very bad writing in this genre is when the author is so in love with his super-tough hero that he just plain forgets to make it seem as though slaughtering dozens of heavily-armed antagonists is dangerous, stressful, or even difficult for him.
At the opposite end of the scale, the softest-boiled private eye I can think of (though admittedly it isn't clear whether or not he actually does this for a living) is the character in the very odd French movie Les Nuits Rouges who thinks it's a good idea to combine the careers of private detective and poet. Also, although no direct reference is made to this and it isn't a plot point, he's obviously gay. Despite being the comedy relief sidekick, he is at times surprisingly competent, and the whole concept of the character is so off-the-wall that I found him far more intriguing than the boringly conventional hero.