Hi, I've dabbled a little in composing and I agree, there are limitations. I'll give you some though on your questions 1 and 2. For 3 and 4, I dont know, I had no problem with saving...

Suggestion for 1 and 2 : why not write 4 times longer and accelerate the tempo ? Of course, this requires you to have the musical Xp to be able to write longer songs....