A few questions about ChangeFPS, FFMpegSource and 25.689 Framerate

[Maikeru-sama]

Let's just assume I am going to use CCE, HCenc or Quenc. Keep in mind this is just me trying to learn more as I know some of the puriest will complain about me burning the subs into the video.

I have some MKV files that have:
Framerate = 25.689 (MediaInfo and Mplayer)
2 Audio
1 Subtitle

Of course, I want to put them on DVD but the 25.689 Framerate is standing in my way.

Now, here are my questions which are based upon the Avisynth Script below:

<SCRIPT>
LoadPlugin("C:\Program Files\DirectVobSub\VSFilter.dll")
FFMpegSource("C:\mymovie.mkv", atrack=0)
LanczosResize(720,480)
ChangeFPS(59.94, sync_audio=true)
SeparateFields()
SelectEvery(4, 0, 3)
Weave()
TextSub("C:\mysubs.srt")
</SCRIPT>

1) Is the signature for ChangeFPS correct or would I just put "true" in for the 2nd parameter?
1a) When the audio is sync'd, how substantial is the change to the audio?
2) Will the subtitles be converted with the "ChangeFPS" or will it be 25.689?
2a) Will Subtitle Workshop allow me to convert ssa->srt with 25.689 Framerate?
3) Why do people make frame rates like 25.689? Is there an advantage to using non-standard frame rates like this?

I will not be able to test for quite some time, that is why I am asking.

[Maikeru-sama]

I finally got some free time and was able to answer most of my questions.

The only question that I have is, is there software that will allow me to convert an SSA file with FPS = 25.689 to SRT with FPS = 25.689?

Subtitle Workshop doesn't seem to allow this type of conversion.

[Maikeru-sama]

Nevermind. I found some software called SubC that does it, although it will not do batch processing.