Yes, IF the rules of proper splicing are followed, dissimilar metals can be successfully spliced.
Some of those rules that I can recall at the moment include:
Yes; it is tinned copper.
Speaker cable can have an insulator that could be any color. The wire inside is typically silver, copper or gold colored.
The copper wire is typically positive. However, the best way to determine which is positive and negative is by referring to the user manual or guide that came with the speakers. The writing on the silver wire is likely there to indicate which wire is positive.
Whichever one you connect to the positive terminal. The colors are there so you can find the same wire at the other end.
The copper wire in silver nitrate forms a heterogeneous mixture. In this case, the copper wire does not dissolve in the silver nitrate, so they physically remain as separate substances within the mixture.
The price of copper today is $3.43 a pound. The price of silver today is $12.90 an ounce. Copper is much cheaper.
When a copper wire is placed in a silver nitrate solution, a redox reaction occurs. Copper atoms from the wire lose electrons to form copper ions in the solution, while silver ions gain electrons to form solid silver. This leads to the deposition of silver metal on the surface of the copper wire.
My PC speaker cables have a copper wire, as well as a insulated (white) copper wire. The headphones (Sony) appear to have 3 wires in them - green, red, and orange. The links you posted are more for car/home theater speaker wire.
Couple options. Strip off a half inch of insulation of the wire were the wire is separated. The splice the wires together. Apply electrical tape to the area that the wires were spliced. Or, replace the whole wire. I recommend replacement.
It doesn't really matter, as long as you connect them to the same polarity at both ends. Most people use the gold or reddish-copper wire as the positive, as it is the red terminal and the silver, or non-colored lead to the negative as it is black.
Black wire to copper screw, white wire to silver screw, bare copper ground wire to green ground screw.
Usually copper, sometimes gold or silver.