What is a bilingual?

Hi there everyone,
I have been lazily getting into this stuff on bilingualism, but find it all very fascinating...
I was quite interested in the great variety of perspectives on what we refer to as a bilingual. I have to admit, that before starting my masters program, I used to think in the lines of the popular view as posited by people such as Bloomfied (1935, as cited in Hamers and Blanc 2000): a bilingual being someone who can speak both languages perfectly. Yet, now I am favoring Grosjean (1985, as cited in Hamers and Blanc 2000) or even Macnamara (1994); a bilingual is more than the sum of the two monolinguals and who posses a minimal competence in one of the skills. This seems to be a richer and deeper definition of the complexity of being bilingual. The Japanese expression for someone who is from two cultures is 'half'. I often joke with people here by saying ~not half...'Double'. 'cause I believe (now this may be controversial, and I hope that I don't offend) that true bilinguals are actually smarter...
I have always been struggling with my identity. Throughout my life I have had a deep feeling of being at least partly Maltese, even though I don't have any physical features that show that I am Maltese. Living in Melbourne, Australia during my formative years must have shaped part of that identity. Even though my language proficiency (...having some understanding of the macro skill of listening, but unfortunately not being able to speak so well) did not match my strong feeling of being Maltese, I was able to feel a strong connection to to culture, and to its language. Every time I heard Maltese, my ears would prick up and I would feel warmth toward it, and some disappointment in not being able to be proficient. My identity must have been heavily influenced by my significant other (mother) when I was a child, to develop a bi-cultural identity, but the context of my social networks and community must have been quite powerful, in that the result is a person who cannot effectively communicate in Maltese (at least in a way that I wish to). It's something that my daughter will have to deal with, too. However, I suspect that she will deal with it in different ways, because of her social context....
ciao
Steve