Also a question about magic armour. If I take a +2 scale armour will that be (could that be) Drakescale Armour +8 +2 as in AV page 7?
Yes, but it doesn't have any mechanical benefit(the +8 is including the enhancement bonus).
So obviously Drakescale is +8 +2 = +10.
I can't imagine any other interpretation
Yes -- it's spelled out explicitly in the table on the bottom right of p. 197 of PHB2.
KS