Earth bonding when changing taps

[jaltapee]

I am about to change the taps on a bathroom sink - the copper piping is connected to the taps by a Yorkshire joint. I am planning to cut the pie low down and connect the taps via a flexible joint (maybe push-fit onto the cut pipe)

My question is, firstly, to unscrew the tap joint will the solder just 'give way' when I apply pressure?

Secondly will I need to earth the new connection? If so, how?

As you may have guessed, I am new to this, so would appreciate any help.

Thanks in advance