AVR-Chat

I am currently writing my programs with Bascom-AVR, they turned out 
to 
be rather big (+1400 lines, including +35 subs). It still works and 
is 
admirably simple( though seems a little slow and needs big stack 
size.) 
I am about to add much more code and I am worry if the whole program 
become too slow or reach stack size limit?!

So my questions are: 
1-
Since I don't have very much spare time (as a hobbyist)in learning 
new 
programming language(and my fear of dealing with complex hardware  
details), do you think it is better for me to stick to the Bascom-Avr 
with my growing program size, or not??

2-
If not, what is my best option? I saw good books on teaching 
CodeVision 
in book stores, but I read on the internet that WinAvr has alot more 
piece of code on the net (I used to copy-paste those  pieces to my 
bascom and it was helpful, so more code samples may be decisive)
Which one has less bug and is more common among C programers?

3- 
Is the C language exactly the same for WinAvr and CodeVision? Are C 
and 
C ANSI Identical? (sorry if specially the last question seems very 
basic)

Thanks in advance for ur reply.