To keep on trying or to just let it be?

Well from looking at your lists, they seem great. The pros are amazing. Now the cons, many you can fix. Let's take a look:

* Stubborn - in which way? Could this be a part of his communication problem, like he doesn't know how to express his opinions so he just stubbornly holds on to it hoping that you'll understand if he keeps repeating the same thing? It's called emotional intelligence, and there are many books on it. Now if he has the problem HE should read the books not you...hope he's a reader.
* No communication - as in he doesn't KNOW how to communicate or just never talks to you about Anything in his life?
* Apathetic - that's a little annoying, I agree. Is it because he's a quiet type? I wouldn't like that...
* Distant - again seems to tie in with no communication and apathetic, you need to find out what is at the route of this - is he not passionate about the relationship, is he depressed, is he not getting enough sleep. Find out the real reason. Ask him straight up, show him you care about his answer. If he shrugs shoulders and says I dunno I'd get worried lol...
* Forgetful - birthdays? or like appointments?
* Busy - that could alwasy be changed IF that's what he belives is right. If he's busy because he's young and is ambitious and is trying to get up in his career, that's something a lot of girls look for. But if he'll be like that for the rest of his life, where he's never home, always busy with friends and work, than I wouldn't put up with it. But maybe he'd compromise IF you let him know that it makes you sad (don't say mad)