Wet fillings in chocolate
To correct your statement:
Water is the arch enemy of liquid chocolate...

You can even let melted chocolate and liquid touch, this will not cause the chocolate to seize, stirring might.

If you want to create a filled bite of chocolate-encased deliciousness often called Belgian praline (but names may vary), you can go different routes: 


Prepare a (semi-)solid centre, e.g. a piece of marzipan or, if firm enugh to cut, your fondant, then coat it by dipping it in tempered chocolate. 
Prepare a hollow shell by pouring tempered chocolate into molds and pouring it out again before it sets. Then fill the shell with your desired filling, leaving a bit of space to the top. Close the shell by piping or pouring more chocolate on it. Let cool between steps and before unmolding. 
For really liquid fillings like liqueur, you need shells that have only a small opening. You can make them yourself, either by using a special mold with a small opening or by making semi-spheres, "glueing" two halves together and then using a warm tool to melt a hole into the ball. Or you can order them from specialized suppliers. Fill the shell with your liquid filling, then close the hole by piping a drop of chocolate on it.
Optional: dip the filled object in chocolate to hide seams etc.