Macbook Pro early 2012 SSD retire block count
The Block count number you have should not be a problem.
Taking some information from The SSD Anthology: Understanding SSDs and New Drives from OCZ
If your SSD has a 20KB block size, that means that there are about about 25,165,824 blocks for a 480GB SDD and thats not including any of the extra storage that some SSD manufactures include. So only haveing 16 bad blocks out all those block does not look like a problem at all, as for a number that would indicate a failing drive, I am not sure what that would be but I can assume that would be the number of extra block the Manufacture provides, once your SSD uses that up, then you start loosing storage capacity.
According to OCZ Product sheet

Vertex 3 2.5” SSD  512GB 480GB VTX3-25SAT3-480G 842024025559

Of Note the 512GB is the Raw Capacity, so it looks like there is 32GB of extra space for block failures, so that works out to about 1,677,721 total extra blocks of storage.
If the drive is causing problems like spinning cursors, slowness or crashes see below for more suggestions.

A possible solution try formatting the SSD 1 more time and try running it with out TRIM enabled or any other 3rd party SSD tools software. See if the drive can work on its own with just a clean install of OS X, with out any weird crashes.

If the drive starts acting up again after the clean install and no 3rd party trim enabler on, it could be that there may be a hardware / software incompatibility between the SATA controller on the Mac and that particular drive. I would try to verify the drive is working OK by placing it in another computer or external hard drive case, etc.
And also try searching around on the web for issues between MacBooks and your particular brand of SSD.

If the drive is acting weird on all testing computers and interfaces, then you would have a confirmed failed drive and would have an evident need of a getting the drive replaced under warranty.


Note: If your having a rough time with the SSD drive it would not be a bad idea contacting OCZ support and explaining to them the issue you are having, they may already have a solution figured out.