Will skinny-leg diode restrict amperage compared to fat-leg bridge rectifier?

There's absolute maximum current capacity, and then there's practical, does it matter in my circuit capacity.  Depending on the current actually flowing there may be an absolute drop in voltage, but it may not matter.  Like, say you detected 0.005 V difference across the wiring.  Would you give up the other reasons for using the advanced rectifier?

Low noise, low forward voltage, fast switching doides are generally preferred in audio.

have you seen the size of the wire in the fuse?

Yes, and i'm actually going to replace 7 low amperage fuses with solid copper rods.  The two main higher amperage fuses i will replace with aliexpress Aucharm fuses...with a rating of 1amp higher than what was taken out...just to get the size of the wire a bit larger.

@erik_squires good point, thanks!  looks like I will now go ahead with my plan!

The 'fat legs' are for mechanical connections to the rectifier, either quick connects or soldering, and do not reflect current carrying capacity. If the diameter of the Cree assembly leads is 1mm or more they will easily carry up to 35 amps. Diodes do not carry steady state current, they only pass 1/2 cycle or else they'd melt.

The two main higher amperage fuses i will replace with aliexpress Aucharm fuses...with a rating of 1amp higher than what was taken out...just to get the size of the wire a bit larger.

Why a correct rated fuse blow at start-up? Think about it!

It blown because it cannot stand the inrush current! Does it also restrict/limiting the current flow and dynamic???

No, a fuse will not restrict current/voltage flow. 

@imhififan there is no fuse that blow at start-up.  I am just exploring amplifier performance enhancements, at the expense of amplifier safety, by bypassing the 7 low amperage internal fuses.  Personal safety (e.g. house burning down) is not compromised because i am keeping the 2 external fuses in place.

there is no fuse that blow at start-up.

Since the mains fuse can pass inrush current which is much higher than the rated value, why worry it will restrict current flow?

I am just exploring amplifier performance enhancements, at the expense of amplifier safety, by bypassing the 7 low amperage internal fuses. Personal safety (e.g. house burning down) is not compromised because i am keeping the 2 external fuses in place.

Experiment is a procedure to support or refute a hypothesis! 👍

BTW, what amplifier it is?