Sony BDP BX1 question for video and audio

[Caesu]

Hi everyone, I was just curious about a few settings in my blu ray player that I would have questions on.

Video related question:

FNR, BNR, MNR settings are default to OFF, should these be adjusted to be turned on in any way. Some movies on my Samsung DLP at certain scenes exhibit a light snow effect grain. I thought this was inherint to the tv, and may still be, however would these settings help adjust the noise. Im at work right now so I cant try it out yet.

Audio Related:

My receiver, a Pioneer vsx1019ahk can decode multiple formats. Should I set it to Downmix PCM or Dolby Digital or the related, Downmix PCM or DTS.

Right now I have them set to Dolby Digital and DTS.

Again, I can try these out for myself, however if anyone can do a quick chime in so Im not wondering about it the whole day, would be helpful.

thanks