If you compile something you'll need some writable storage mounted anyway, so
you will be able to add the libraries.
No that I don't believe you should expect too much about this, some (most) apps building process just don't take cross-compilation into account or worse need some porting work to run on arm.
A LiveCD will be a convenient way to have the sdk set up without doing anything, compiling the application of your dream might still not be straightforward.
For instance w3m compiles a small helper apps during that it runs afteward during the build process, if you cross compile it, it doesn't work because the helper apps is compiled for arm. So you have to work around, compile the helper app for your build platfrom, tweak the makefiles etc...
The only way to have a no frill cross-SDK would be to provide fixes/patches for all the applications that causes troubles.....