Not going to argue what's ultimately a matter of personal preference, but since you asked...
> Sorry, that's not my philosophy. If you set #ZTTools
> to %#ZTHome%\.. you pack every tool in that parent directory?
Some, yes, mostly single-file tools like "rar.exe". Other multi-file packages, no. For example, I use "%#ZTTools%\eps\epsilon.exe" or simply "eps\epsilon.exe" to point to my favorite editor.
> Why can't ZTree firstly search in the #ZTTools directory, if unsuccessful, call
> the system path? That wouldn't touch your solution but enhance the possibilities.
If ZTree searched #ZTTools first, unconditionally, and if some tool existed *both* in #ZTTools *and* somewhere else in the %PATH%, then there would be no (easy) way to call the one in the %PATH%. The way it works now, if I enter it as "rar.exe" then ZTree looks for whatever "rar.exe" can find in the default path, otherwise if it's "%#ZTTools%\rar.exe" then it only uses the one in that specific location. That leaves the choice to me, and I appreciate having choices.
Cheers,
Liviu