Some questions about Galapagos

Hi to all..

I'm interesting on Galapagos because I use it for my thesis and I want to clarify some doubt.(I read the David Rutten Article on his blog)

1)What kind of code does Galapagos use? Is it a binary code?
2) Selection;there are 3 kind of selection that SW can uses (iso, topN%,Bias), my question is: when Galapagos uses each of them? for example(i don't know) at the beginning the SW uses iso, or when the pressure is low the SW uses bias..
3) Coalescence; There are 3 kind of coalescence ( corssover, interpolation, interpolation by weight factor), my question is: when galapagos uses each of them?
If it's possible for question 2 e 3 I just want to know the philosophy followed by the SW to choose one of the possible choice.
thank you very much

4) are there any relationships between the number of genes and the settings parameters( population, initial boost, mantaining, inbreeding factor)?
Best regards,

Flavio