I'm curious, why is the reasoning of the u sound and the o sound with the umlaut that sounds like a u. Same sounding, why two differing letters?
It's not an umlaut, umlaut is two dots :) Let's call it an accent, although it's a major simplification.
The pronunciation used to be different, more like a long o. Over the centuries it became identical to u, but the way of writing it stayed.
Would "Kocham mojego kraja" work? I'm not a grammar guru, but it kinda sounds like "Kocham mojego brata", which also sounds ok to me.
Not unless you are drunk – the difference between „kraj” and „brat” is that „kraj” is masculine-inanimate and „brat” is masculine-personal and that's precisely why one work with ending 'a' and the other doesn't.
Grammatical gender really matters, unfortunately. ;)
Edit: BTW, it's only a half-joke – it's relatively common for native speakers to 'animate' words that aren't animate when inebriated.
I would prefer 'wieś' or 'miasto', as there is too much nationalism everywhere, and i only come to learn the language. I mean, i live in Poland and love Żuk vans, but I do not suppose you plan to cater for the interests of people like me, so why are nationalists so special?