basic question of GCJ

[Steve Ni]

I am newbie of GCJ, I am really grateful to for GCJ developers' greet job!
I have some questions:
1)I have read some spec.&FAQ. It seems GCJ group rewrote all code in Sun
JDK's java.* and javax.* class(generally, found in Sun's rt.jar). I really
wonder if it's good way. As known, most programmers of Java develop their
projects by Sun JDK, maybe 1.3.x or 1.4.x. Sun JDK already published for
years, and too many bugs in rt.jar were fixed during these years. If GCJ
rewrite all java.* or javax.* package, could you gurantee these package is
stable like Sun's ? And Sun release some new java.* api in JDK1.4, for
example: java.nio.*, how can I use those new API?
Is it possible that I compile my code with java.* and javax.* in Sun's
rt.jar( certainly, except AWT&SWING) instead of GCJ's libgcj provided?

2)I have a project, look like:
my.jar and some *.c -- my project source code, I own java and JNI
sourcecode.
jmf.jar and some dll (java media framework in window platform) -- I only
have class and *.dll files
other.jar -- some open source project, I have their source code.

It also can be accecpted if I just compile my source code and leave jmf as
class package. Is it possible compile my project by GCJ?

3) When I release my project, are there some additional library requried?
Furthermore, I just want to confirm my concept of GCJ: when running my
compiled project, for example, input "myprj" to startup program, when mypri
execute to some class file(As above mentioned, if I leave jmf as classes
package. ), does it load those classes automatically? Is gij required?

Thanks a lot !
Steve Ni