not to sure about how polycount for a creature or a mob should be the less is always better i guess but it has to have some detail not to happy with the face of the goblin it should be rounded more but then i have a whole polyrow more i think

and the spider legs where ment to have the cuts to deform when rigged i pretty much know the basics for riging and skinning it but never actualy done it, and for a game model not sure bout how to do it just rig it and the program its used in set animations or build in several small animations that the program takes from the total animation to use