The "problem" that you encountered with the space has nothing to do with pifont or any other package. In general, with any command, you have to tell TeX/LaTeX where the command has ended. If you have a character that cannot be part of a command (like the brackets, the numbers etc, unless you change their default
\catcode), occurence of such a character would automatically tell TeX/LaTeX that the command has ended before this character. This happens in the example
But if you write
then TeX/LaTeX does not know that the command has ended after you wrote "
\cross". It goes forward, and sees a blank space, and then it knows that the command has ended. After that, there is no space, so it does not separate the cross and the letter A. If you write
you will obtain a space. Or if you write
that will also do. There is no need to use packages for such simple things.