I think only I have the answers for you...
1) Your real voice cannot go beyind your falsetto, but the real voice can be pushed, of course till a certain limit. Its an improvement of one or two notes more for you I guess. thats human limitation.
The fact is your high voice can intersect into your falsetto, which means you have the option, if you have the range, to choose between using real or fake voice if tat note is in the intersection range. With that, you could also lower your fake voice, by using softer amt of air control. I have answered here:
http://soft.com.sg/forum/all-about-...-raise-your-vocal-range-hit-those-keys-2.html
For your real voice to hit a new high, it will take practise of the above method, again and again. It is muscles, like training pull-ups you know...
2) I can't comment cos I never hear you sing before and how you run out of voice, but one common reason is lack of air, which is caused by interchanging usage of lung and diagphram voice inproperly.
Another reason is probably you didn't hear the music's key properly ? So it's a matter or hearing, not singing.
3) When you change high real voice to falsetto, you have to control your amt of air, because falsetto don;t require alot of air output. So when you switch, you must consider the air volume.
Try doing an exercise when you go "do re mi" up and down between real voice and fake voice. When you push with alot of air to your max real voice, and the next note is
falsetto, you must control, so the transition is smooth. Likewise for coming down from falsetto to your real voice, its not easy, again you must control, especially the switching part.
You will also realise the going up and coming down switching is on a different note. Its ok as long as you control properly, it will sound very nice.
4) I think you solve 1,23 problems before hitting this. No point sing badly but vibrato at the end of every phrase tail. What I can tell you is, it's like learning how to cycle. It's natural once you learn how to vibrato. So my vibrato a forced out one, its natural, but very hard to explain to you here..
Hmm, I think my video here answers your questions. I know its bad, but its one of the best to answer your questions... Do note all the little vibrato... the falsetoo, the projection of high real voice.
http://www.youtube.com/watch?v=MLu4u2yG_bE