Present perfect continuous/present continuous

Let's say I just came at a party and heard a conversation between two girls. One of 'em said "I've been trying to do it.". I wouldn't understand if she was still trying or not.
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I have always loved you. - I have always thought this means that I still love you. Am I right?
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I've been trying really hard to do it.
I'm trying really hard to do it.

Could I use either one if I were still trying to do it? If so, which one is better?

What do I do when it comes time to decide between present perfect continuous and present continuous as in the examples above?

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I've got to make sure. Do native speakers really not thing about the future when someone uses "I have been + verb + ing."? That's REALLY strange. Will context tell me if someone is still trying/doing/thinking etc?

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Are you gettin' enough sleep? - Does this mean something like: Are you gettin' enough sleep these days/lately?

I'm having way too much fun with you and Elena here. - When the speaker uttered the sentence, he had been in town for like three days or so. Why did he use "I'm having"?
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I'm reading a really good book these days/lately.
I have been reading a really good book these days/lately.

Which tense is better with these days/lately? Present perfect continuous or present continuous and why? I don't know why, but I'd use present perfect continuous. It may be because it sounds better. I don't know why, though.
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He looks as if he's having fun. - Right now. This version is the standard one in BrE and all of my friends use it. I do, too. I was told that this version was substandard in AmE. So, my question is, can I continue using it even though it's a substandard version?

He looks as if he was having fun. - This sounds wrong to me. I would never use this one because the "looks" in the sentence does not match the second part of the sentence. And by doesn't match I mean the tenses.

He looked as if he was having fun. - I'd use this one if I were talking about the past. Am I right?

What tense is the best after "as if"? I've looked it up in lots of online guides and all of them have given me different definitions. A native speaker whose native language is BrE told me that this was the area in English language that was changing and that might be the reason why lots of people have different opinions on it.
What do you think?