Faster Than Light is FTL, not FLT. Of course, that can also be For The Loss, colloquially.
In general, I agree with you about context recognition. LEO can be Low Earth Orbit or Law Enforcement Officer, but we rarely find ourselves in a situation that seriously confuses the two.
I posted this in the comments at Eric Raymond's blog:
Then I realized some here may find it useful.
Extensive use of abbreviations and acronyms was primarily a convenience for writers, when writing was done by hand and then by typewriter, there is less justification for it now when most writing is done by computer. And as my comment points out it is usually a negative for readers. It does benefit readers when you can convert a long phrase into a readable word, SCUBA and LASER spring to mind, but that doesn't occur often.