Re: InDesign preflight tools?
Flightcheck could use some rework, but I find it fine. A good timesaver, especially if you are dealing with third party-supplied files.
If you are primarily creating PDFs for output, though, you may want to look into PitStop. I get good recommendations from some techs for this (can do some repair work as well), especially since many PDFs can have issues if not set up properly. Unfortunately, I cannot control this, being in a publication environment (ads submitted), so it's good to have tools that can handle this.