changing wires in Z560

I bought a pair of Z560 and they are on the way, I read they have a gauge 18 cable (wich translate to 1.024mm).
and I've been suggested to change it to 16 (1.3mm) or 14 (1.6mm) or 12 (2mm).

this of course would lower their resistance, and maybe increase the current? and how does that improve sound quality?

is there any risk in shortening the speaker's like that way?

I have some spare electrical cable of many size, even the 2mm (12 gauge) so I could use it, but I've been told I'd need banana's plugs that way. is it to improve the connection to the speaker? do I need a very good banana plug , are the "normal ones" below the quality of just connecting the cables without?
if they come in differente materials, what is it I should know to choose the right one?

thanks for any explanation,guys!

because I read in a review they are not soldered in the speakers, they are pinched just so you can replace them easily with better cables.and many ppl infact change them.