MacBook stolen / iCloud action?

[mojolicious]

Not sure what the best subforum is for this one...

Suffered an opportunistic burglary last night in which we lost a mid 2010 MacBook (amongst other things).

Is running OS X 10.9.5. Has no EFI/BIOS/firmware/whatever password set, and has four passworded user accounts. Find My Mac is enabled.

Obviously the laptop itself is of no great financial value, but it's stuffed full of saved Safari passwords (which I'm in the process of changing) and, in my case, eighteen years' worth of locally stored mail which I'd really rather someone else didn't have access to!

Via iCloud I've set the MacBook to 'erase' when next connected to the internet. However my daughters tell me it's got 'unique' school work on it. Given that there's a possibility, however slim, that the MacBook might be returned, is the 'erase' option actually any more secure than a six digit iCloud lockout? Or is just 'locking' the laptop sufficient?

If someone is feeling really curious, presumably moving the SSD to another host and booting from an installer image would allow the resetting of account passwords, thereby circumventing those passwords and both 'lock' and 'erase' set via iCloud?

EDIT: looking at Find My Mac it appears there's no way back from 'erase pending'. Just a word of warning to waverers!

 

[mojolicious]

Okay... after a webchat with Apple, it appears that:

a) there's no way that an 'erase' can be cancelled, and

b) an erase command sent via iCloud will erase the disk, give it a fresh OS install, and also restore the admin login (ID501, presumably?), which means if the MacBook is later recovered, powered up, and connected to the internet, then it will magically reappear in Find My iPhone.

So there *is* some hope. One of the reasons I wanted it locked rather than erased was that the MacBook had a replacement rubberised baseplate and therefore had no visible serial number to associate it with the crime report.