True. What's easier to master? A foreign or native language?

I began learning Spanish in nineteen seventy after a fellow Brit said how rude we Brits are expecting everybody to understand English. So when I returned from Lloret de Mar in September I commenced learning. By Christmas I'd got a bit behind and packed it up. However in mid-January we were called out on strike which lasted until early March so I resumed my studies. I now manage fairly well but I still continue looking-up points of grammar, especially when I'm corrected by my Spanish señora, or my daughter who has an 'A' level in Spanish and used to live in Alicante!

I think it is easier to master your native tongue, but you can always get a high level of proficiency in other languages as well... :-)

Could someone LOVE a language but not like the country?

Of course. You may love English but hate USA, and love India or Jamaica or Australia or The Philippines or UK. The same would go for Spanish: hate Spain but love Argentina or Mexico or USA... Or you can dislike all those countries, and just have a love for the language. There's lots of variables.

Reading a Spanish book in England seems different to reading one in Spain. Why?

I don't think I would notice the difference, but speaking Castilian in Spain is different from speaking Spanish in NYC for me.

Why is it different? :)

The vocabulary and accent is quite different, and I am more accustomed to conversing with new-world Spanish speakers .

I have little trouble understanding well educated Hispanophones regardless of where they're from, however I do occasionally struggle to follow ill-educated people with marked regional accents, whether they're European or Latin American.

That's not snobbery at all by the way, I hold very liberal views. I actually have as much difficulty with really strong local English accents. The far north east of England has a very marked accent almost incomprehensible to the rest of the UK - 'Geordie' it's called.