[pLuhhmm]

Okay, so I have a Creative Sound Blaster Z, FiiO E09k amp, M-Audio M10 speakers, and DT 990 250ohm headphones.
The amp has a headphone port which uses the built in amp on the sound card and surround sound ports. Not sure which to use.
 

 

[NA Blur]

Use the headphone / Front for headphones and the others for surround setups that have multiple speakers.
 
There should also be surround sound settings in the software you can play with, but you have to first enable "Speakers" in your audio device manager.
 
If the volume does not get loud enough will need to increase it in your player, device manager, or adjust the gain.

 

[pLuhhmm]

Currently, I have a 3.5mm plugged into the first 3.5mm port next to the headphone jack, that goes into an 3.5mm to RCA adapter, which then goes into my FiiO E09k AUX IN, then from there my speakers are connected to the LINE OUT, and headphones into the FiiO headphone output in the front.
 
Is it fine to use the amp powered jack on the sound card and the FiiO E09k amp? I don't want to have to switch between sources for the speakers and headphones, and I want to use my volume dial on the FiiO. Is there any negatives to how it's currently setup?
 
In Creative control panel, it's also configured as Stereo (2.0/2.1) speakers instead of the headphone option.

 

[NA Blur]

No, but you are double amping the signal because you are taking the amped analog signal from the soundcard and amping that with the FiiO. Not that this is a bad thing, but if you notice anything funny this might be a good place to start looking.
 
I like your solution.

 

[yage]

  Currently, I have a 3.5mm plugged into the first 3.5mm port next to the headphone jack, that goes into an 3.5mm to RCA adapter, which then goes into my FiiO E09k AUX IN, then from there my speakers are connected to the LINE OUT, and headphones into the FiiO headphone output in the front.
 

 
You aren't double amping anything. If I understand you correctly, you're using the line-level Front L/R from the Sound Blaster to the E09K stereo input and then back out to the powered monitors via Line Out on the E09K. Sounds like you've got everything hooked up correctly to me.