Perhaps I'm out of sell by date but always thought that terms 2, 3 & 5 were used for extensions.
As for the 6 wire, as long as the same colour wire is in same terminal of each extension.
For ease of I.D use three main colours throughout as follows
term 2 Blue/white
Term 3 Green/white
term 5 Orange/white
This eliminates 'Did I fit Blue/white to 2 or 5? You know with above 2 throughout is blue/white 3 Green/white and 5 Orange/white.
T is right you need an ADSL for each socket using a comunication instrument.
BB
November 2009