When Im practicing my pull-offs I have noticed that when I pull-off with either my third or fourth finger to my first finger I seem to be bending the pitch of the string while doing this...
It seems when I do the "flick off" motion with my third finger that it's pulling the string down and bending the pitch of the string...
I've also noticed this does not happen on the first string nor when I pull off from my 2nd to first finger...I'm not sure what I'm doing wrong other than maybe flicking the string too hard when I pull off or maybe not applying enough pressure with my first finger???

Any suggestions on what I'm doing wrong and what to work on to fix this would be greatly appreciated...
one thing that you could try is avoid the flicking motion all together, classical guitarists have some of the best legato in the world and what makes them different from nowadays players is that they pull off into the wood of the guitar,
its hard to describe but instead of pullin your finger off the fret board and up in the "flicking" motion pull off into the wood of the neck so that your finger doesnt come up, this might fix the problem, but overall just keep practicing until your fingers get strong enough to where you dont have to grip the string so much when pullling off
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You're probably playing with a little too much tension, and this is causing you to pull off with too much force. Just keep practicing lots of legato, focus on relaxing, and using only the amount of force necessary to get the note to sound and no more.
I've experimented with the classical legato approach Jman09 mentions too. I'm not sure about completely reworking my legato to use this instead of the normal rock/blues approach, but it would definately an interesting technique to work into your playing. You can achieve some extremely economical legato with it, with no sharpening of the notes at all. You basically push your finger from the string to the gap between the strings downward towards the floor. There's a really good post about it from about a year ago by edg (who sadly no longer seems to post here - the guy really knew his stuff).