In short, Yes. The coil packs produce a very stong spark. The spark plugs are gapped to take advantage of this. But because of the stong spark, it is easy for it to leak out if the wires are old. The PCM will not throw a DTC until the misfires exceed a level that will damage the cats.
Poor performance could also be from an EGR valve stuck open.
Don't you have an ODB2 scanner? Graph the LTFT1/2 and RPM's. Looking for LTFT's that switch from idle to load. Also looking for differences between bank 1/2.
For example, one prime symptom of MAF contamination is an AF ration that is rich at idle and lean under load. The PCM respond by taking away fuel at idle and adding fuel under load.
One symptom of a vacuum leak is a LTFT that goes from very big postive values at idle to not as big positive values under load. Therefore, if your LTFT are -17, this is not normally associated with a vacuum leak.
So... just stating that the LTFT is -17% with no other details really short cuts process.
IMO, you are silly to drive this car if you actually suspect a bent valve. Expect to have a new pile of metal scrap should the value keepers give way and the value drop into the cylinder.
Very silly considering the relatively low price of a Harborfreight compression tester. Even more silly if the tool is rented.
2003 GT Convertible (sold & missed)
2000 GT coupe (Craigslist project. Fixed. Now my DD). Windsor to Romeo swap.