Major concern: no realistic chance of killing/injuring innocents.
At this point, Batman has been 'dead' for about 36 hours. They figure Bruce can be out of the public eye for about a week maximum before folks start to wonder. (It's minorly AU in that Bruce does tend to spend more time at WE and isn't likely to run off globetrotting for months the way he has for certain DC canon storylines.)
I have two ideas, but I don't know enough about the little details to figure out what's involved.
The first, I don't actually expect to work, but I want to write them discussing the idea and rejecting it BECAUSE it wouldn't work. Specifically, to find out whether a passenger plane has crashed recently, hack the passenger list, and insert Bruce's name. One major problem that I can see with this idea is that even if this wasn't true prior to 9/11, I'm guessing that nowadays airport security feeds would show the passengers boarding. Now, I'm guessing that someone with the technical expertise could possibly doctor the records a la Forrest Gump to insert Bruce onto the footage... but how many tapes/discs/etc would need to be tampered with? Could this be done remotely, or would someone need to basically steal the originals and substitute copies?
The second... I was thinking that they could completely destroy his private yacht, with Bruce and all (imaginary) crew believed onboard. Given that Gotham City is either in NY or NJ, a hurricane/tropical storm would be more unrealistic than the plane crash scenario. So what could theoretically burn/explode a yacht too quickly for all hands to abandon ship? If need be, I can plant signs that a drunken Bruce took the yacht out alone and ended up drifting to open sea before the destruction. What I need to know is what it would take to turn the craft to smithereens that would quickly be ruled an accident?
Apologies, I normally do try google first, but I wasn't really sure how to get started on this one.