A danger they are already in, by being engineers at Apple. They could just as easily be whisked away by one of these nefarious foreign Governments/Criminal Organizations and be brutally tortured in perpetuity to do whatever the hell said individuals want.
You also fail to explain how these engineers escaped the clear and present danger to their lives, over the past decade+ that Apple's phones have had market dominance. Especially given that the world over has known they have the capacity to breach said devices, up until they altered the software in 2014.
I liken this to the GoP in the US, altering voting laws to prevent voter fraud, when the volume of voter fraud is so small it couldn't effect the outcome of a village election, let alone a nationwide election. Likewise here, it's quite clear Apple only did this to try and absolve themselves from any responsibility in assisting the Government in criminal cases where an absurdly narrow focus warrants access (which, frankly, I don't have words for how disgusting that is).
No it's not a danger that they currently face, as they do not possess the knowledge yet. What's being asked to be done isn't easy. The FBI has given vague descriptions of how they think it'll work, but offer no real implementation.
Apple did it to protect their brand following the NSA fallout. They didn't do it to absolve themselves responsibility, that's a mad claim, if anything the legal burden on them has been made harder through this system. Apple increased data security around the same time that all tech companies did, because data security has been splashed across the international media, and it had serious implications on companies' bottom lines.
They claim to not possess the knowledge, however, if it weren't possible they would've said it's not possible. Which probably would've made this situation a tad easier for them. The FBI has merely asked them to remove the function that erases the device after 10 incorrect attempts at the password. There is nothing vague about that request, nor is there really any question as to how it'd work. Here, I'll throw out an easy solution -> Apple would create the update, it would rest in their systems (likely a standalone in-house) until a warrant was issued under certain criteria that a judge has ok'd, Apple would trigger the update process to that device and have it update itself with their custom OS. <-- The FBI would then be free to attempt to brute force hack the device, w/o having to worry about the data being erased. There is nothing vague about this. There is no mystery about the process, it's actually very simple and I find it difficult to believe it's actually a hard thing to do. And, under this solution, the update would have to come from Apple, it wouldn't be something you just load onto the device via a thumb drive or something. Hell, they could require the device be brought to Apple headquarters, and the update done at the standalone terminal. And you still haven't addressed the fact that Apple had unlocked phones in the past under previous warrants, and no nefarious entities obtained said keys (The NSA/CIA etc.. had their own methods, at the time).
Again, this is a very specific request made PUBLICLY by the FBI, regarding a deceased employee of a county, and Apple is refusing to assist a client with accessing a device they legally own. Once again, the deceased do not have a right to privacy.
This is not the NSA, this is not the CIA, it's the FBI, submitted through proper channels, to a judge, and the judge has agreed to the request. You realize these laws were also put in place, after the NSA fallout, right? We all wanted to have a very tight leash on when a Government agency could access our electronics devices, well, they have a tight leash, and the Judge agreed this is a situation where they are functioning within the boundaries of said leash.