How ship gcc binaries and recompile whole gcc for additional gcc language support

[mfe userlast <mfe at live dot de>]

Greetings,
I'm trying to build gcc 7.1.0 on a NetgearReadyNASDuo (http://wiki.dietpc.org/index.php/DIET-PC_on_SPARC_ReadyNAS).

The netgear readynas duo is shipped with gcc 3. I upgraded the necessary libraries to the last version:
mpc, gmp, mpfr, m4, automake, libiconv, libtool,bison, ncurses,libxml,gettext, ils...

My next move was to upgrade and install gcc from version 4.0 to 4.6 and than I continued with gcc 4.6 version to gcc 7.1.
I thought I'm safer upgrading gcc with the above steps than upgrading directly from gcc 3 version to 7.1.

I built gcc 7.1. with ../gcc-7.1.0/configure CC=/opt/gcc-4.6/bin/gcc CXX=/opt/gcc-4.6/bin/g++ --enable-languages=c,c++ --prefix=/opt/gcc-7.1  --with-cpu=v7 --with-mpc=/usr/local  --with-mpfr=/usr/local --with-gmp=/usr/local --with-isl=/usr/local/ --disable-libstdcxx-pch  --disable-linux-futex

If I want to ship this gcc version to the same NAS netgear model, is it enough to ship all files in /opt/gcc-7.1 with the necessary libaires like mpc, gmp, mpfr...? Or do I need the assemblies of gcc 4.6 and gcc 4.0 too?

My second question:
If I wan to add additional language support for gcc like ada, go and so on, do I need to recompile the whole gcc?  Do I need to execute make distclean, reconfigure and recompile gcc again?

Is it enough to reconfigure gcc with --enable-languages=go or --enable-languages=java or do I have to set the existing languages for c and c++ again. So should it be enable-languages=c,c++,go?

Thanks for your help
best regards
Martin