Yeah, his joints should be connected, I can see holes in his body when he's breathing, attacking and standing.
that's because he's working in 3dsmax 5. The joints will unite once he exports the model.
About the animations:
1º the legs are static in stand-1, they need to be a lil bit, and the pelvis should have some slight movement since the spine is breathing.
2º Stand - 2's start is very fast, it won't blend well in game. Insert like 10 frames using dope sheet and make him raise the staff to his shoulder with less desperation.
3º Walk, the feet don't touch the grown correctly. Also, his right arm looks pretty stiff, it's not very natural, it looks like some robotic arm.
4º Remake Stand Ready. The position is bad, his legs are way too open, his arms are badly positioned, the left arm collapses with the chest and the right arm is way too much in the back side. The animation also doesn't blend correctly.
5º The attack animation looks kinda stiff, it has a good amount of motion, but lacks motion in the pelvis. the feet aren't touching the ground correctly and in general they appear like doing tiny circles in their grounding area. Also, the front leg shouldn't go up and down, it should remain stiff and the foreleg and upperleg should bend according the body's movements. Another thing, the arms are collapsing with each other, this shouldn't happen, you should make sure that the arms keep the same relative position to the staff during the whole animation. As an end note, the animation does not blend. You may have to remake it after remaking Stand Ready.