Is it best to sculpt limbs and sections separately? How do i connect them?
Say…I want a lot of detail on the torso, hands, and head…But the arms/legs don’t need as much detail.
And is it best to apply the multirez or leave it be? 
One more thing…Can I sculpt wrinkles into clothing if i wanted to animate it? How would I make the wrinkles real?
I suspect you are not getting many replies because you have asked too many questions at once.
Animating sculpted characters is difficult if they are at a high level of multi-res. Deformations are difficult to tweak and control. I usually try to bake sculpted detail down into a normal map.
Seperating limbs, I’ve never done it, I have seperated the head for fine detail though. Reconnecting will either require keeping vert loops consistent between the pieces, or simply hiding the disconnect under the clothes. Look at Angela’s Sintel model and it’s construction.
And for the cloth you could run a cloth sim.