its better to set your paths by using the vcvars32.bat
The set commands I listed above include the vcvars32.bat commands. But the vcvars32.bat does not set the environment for the SDK, only the Toolkit so it is not sufficienct by itself. You can save the set commands listed above as a batch file and run that *instead* of vcvars32.bat, or, as you point out, you can put these permanently in your enviornment (do as demerphq advices to make a diff, then, right click on my computer, select properties-advanced, select environment variables, find the PATH, LIB, and INCLUDE vars and set them with the output of the diff, or as I show above).
If you want to avoid pain, don't put spaces in the install paths
While I am sure you are right for most paths that have to do with perl, I do not believe that the spaces make any difference when they are meant (as the ones in the set commands above are) exclusively for use by windows. OTOH, the spaces bit me (and you helped me, thanks) when I tried to put the perl build (the one I unsuccessfully tried to build manually) in a directory with spaces. Your advice is probably safest as a general policy, but I really don't think it should or does make any difference for the compiler tools.