Thanks for the praise everyone.
You do run into the enhancement cap if you don't have a torso with the 10 agility elf. If you get one though then you can totally have 15 agility. Personally, high agility elves are better off going with Muscle Toner and Superthyroid than cyberarms though.
As for Metagenetic Improvement, it's basically 10 BP. The SURGE quality provides BP cost * 2 in positive qualities. So SURGE II costs 10 BP and gives you 20 BP that can spent on positive qualities off a certain list. So you get SURGE II for 10 BP, spend the 20 BP you then get on Metagentic Improvement. You get +1 to an attribute and raise its natural maximum at the same time.
Now SURGE requires you to take negative qualities equal to the bonus BP, but honesrly that's not really a drawback in SR.