Questions about controllers and some hardware modding

[fandangos]

I just want to clarify a few things before I screw something here.

I have a VA1 with the voltage regulator for the 12v line removed and the USB GD-ROM installed.
I'm having a hard time with my controllers, I have 5 and while the VMU lights up, none works or works for a few seconds and stop, or hangs at down key.
Weird part is, I have the official arcade stick and this one works flawlessly!
I'm considering replacing the fuse with a new one but here in my country I can only find polyswitches that are reversible up to 300mA and I've been reading that the DC uses 390mA.
It should be fine replacing it, right?

Next I've ordered a vertical battery holder to replace the rechargeable one from the DC.
It has 3 legs, + - and another point. I guess the third one is used to recharge the battery?
Can I just solder 2 legs and use a CR2032 that is not rechargeable?
Or do I really need to get thee LM2032?

And finally, I don't have access to 3D printing and I can't find that small noctua fan here.
Is it really a problem to run the DC without a fan?
Or is there any tutorial to adapt other fans into the DC without 3D printing plastic holders?

Thanks in advance to whoever reads this post till here.