Cross compilation works for the kernel and packages with no dependencies like xz but as soon as you build packages depending on tcz's you can not manage it, or on a complicated way wasting much more time than you win. If you have few packeges to build, start compilation and take coffe, go to cinema, etc. If you have many, buy RPi2 or RPi3. But forget cross compilation at all.
I tried several times and gave up, using it for kernel only.