As an example of how you can run 32-bit application software on a 64-bit operating system is Slackware. Slackware is released in two "pure" forms, 64-bit and 32-bit. If you've installed 64-bit Slackware, 32-bit won't run; however, you can install a set of packages that add 32-bit libraries to Slackware 64-bit so that 32-bit software can execute.
Solaris has been 64-bit for years and years but it comes with 32-bit libraries already installed and will detect a 32-bit binary and link the 32-bit libraries needed. Slackware does essentially the same thing in slightly different ways.
What Slackware does is the 64-bit libraries are in directories such as
/usr/lib64 and
/lib64. With the installation of 32-bit, the necessary 32-bit are installed in
/lib and
/usr/lib (where they're found on a 32-bit system).
One of the Slackware developers, Eric Hameleers, who goes by the alias
AlienBOB, developed and supports what he has called
multilib, explained at
http://www.slackware.com/~alien/multilib/. Multilib allows you to run
and compile 32-bit software on a Slackware 64-bit system.
Essentially, you cannot run 32-bit on a 64-bit system without doing something similar to
multilib (if that capability was not installed by the distribution in the first place); i.e., you must have 32-bit libraries available for a 32-bit binary to execute.
You do not want to remove GCC -- if you do, you'll never be able to build a kernel or any other software from source (or install, say,
VirtualBox which has to build kernel modules on the platform).
As an alternative you might want to install VirtualBox and install the 32-bit version of the operating system you need to run your 32-bit application as a guest operating system (that will work just fine, you can install and use a 32-bit operating system on 64-bit hardware). That may be your best bet -- but don't go removing software where you might wind up with a boat anchor or expensive door stop.
Hope this helps some.