#1
I'm new to using FX pedals and my only effects besides a crybaby has been a Digitech GNX1 which is sh*t. With these effects, what would be the best way to position them?

ISP Decimator noise reduction pedal
EHX Small Clone Chorus
Korg Pitchblack tuner
Crybaby wah

I'm pretty sure the tuner should be closest to my guitar.

I've heard of people putting the Decimator before the other FX, after the other FX, or in the FX loop. I'm using a pedal board, so I really don't want to put it in the FX loop.
#2
Like you said, tuners are usually supposed to go closest to the guitar so that you get the most pure, unmodified signal to the tuner you can.

If you wanted to avoid using the effects loop, I'd probably go:

Guitar -> Tuner -> Wah -> Chorus -> ISP -> Amp

If you have an effects loop, you really should consider running the chorus in the loop; modulation effects often sound better after the pre-amp.