ive been planning on porting a rancor into swbf full sized. i aligned the skeleton to the bones, envoloped, and when i try to export the basepose or the mesh itself, the bones reset back to original size and location. why?

did you export with the "exort current frame as basepose"-option checked?
and second: you can change the length of the bones only through the slider in the propertypage, not by scaling them normally. on export the bones get reset to their neutral or reference pose (you can set these under animae:create:skeleton->set neutral pose). however setting a new neutral pose is only important when enveloping a unit that is not in t-pose, the bonerotations in the basepose dont matter, they are solely controlled by the anims.

ok the neutral pose thing worked but when i export the skeleton still goes back to its normal size. (i used kinemetics scale)

you cant, you have to use the lenghtproperty of the bones.

If you're trying to adjust the unit_template to fit the geometry then to make things easier just remove all animation from the skeleton and move bone_root into the new position first(the rest of the skeleton will move with it since it is the parent), then use the Move Joint Tool(ctrl+j) to adjust bone lengths interactively in the 3d viewport until it matches the geometry(use the ppg to fine-tune it), re-apply the keys to the skeleton after enveloping/weighting then export your entire hierarchy and a new basepose as well.