Will HK spawn in my world if I already progressed, because I can't seem to find him? I downloaded this along the main mod. Also I have created a new world to test if it was even working and I found him after a couple of seconds.

Just tested a few scenarios. So, if HK does not spawn:

1. Look around town, not in any buildings other than Bar, but I've seen him Patrolling around the walls and then goes to the Bar. He will engage in fights so it's possible he got pulled by some enemies at the Walls or Gates, though I have not seen that happen yet.

2. He's Unique so only one will spawn per game(not including hk races you start with). Unless you use the Move Squad trick.

3. If it seems like he is just not showing up. Move all Characters out of The HUB, Save(new), Restart and Import Save(new).

I found him but I can't talk to him. Do I have to kidnap and recruit him that way?

@Bacon
Sometimes he will not talk until he get in the Bar and Sits down. Other than that, try #3 above

HK does not mesh very well with clothing of any type, any sort of patch coming to fix this?

@tollersauce
The HK Mesh is not from my Mod. So, no. The HK Droid Race Mod author has updated his Mod a few times and they have all been Mesh updates. Those updates do automatically apply to my Mod