Since you are execVMing the script, there is no reason to spawn the section of the script with the pausing in it.
Assuming the script was run with call, though, you might want to continue using the spawn, but you would want to do it this way, in order to ensure that the privates were created inside the new spawned script, not outside it (where they are actually completely ignored):
if (!isServer) exitWith {};
// Pass _this into the inner script without using it:
_this spawn
{
private ["_showUnit", "_showTime", "_showMarker", "_markerName"];
_showUnit = _this select 0;
_showTime = _this select 1;
// etc...