[Trisquel-users] New installation - Some "settling in" questions

[yeayea542]

So for reasons unknown my last installation of Mint bricked so I shopped  
around for a bit and settled on Trisquel. I'm liking it but there are some  
things I'm trying to get working.

-Keyboard shortcuts are not a thing. I'm using a laptop and it has shortcut  
keys for things like adjusting volume, screen brightness, etc. How can I get  
these working again?

-Is there any way to get the "search" bar for the Menu where it'll search  
through installed programs to find what you're typing in?

-On Mint I used BleachBit to help control the proliferation of junk files.  
Does Trisquel have something similar or can I install BleachBit?

-IceCat doesn't seem to like certain Firefox extensions. Is there a way to  
get IceCat to read them or am I going to have to download Firefox?

Thanks in advance.