My approach is to have everything in curly braces. When using an expression builder – which is the best way to avoid typos and hard to detect bugs – everything you type in is put in braces, anyway.
As for the Empire Forcepool, you would use CurrentMap = $starname$ + " Forcepool". If it does not work, try $starname$" Forcepool". I’ve had similar problem and the latter approach worked (https://forum.vassalengine.org/t/piece-dynamic-properties-send-to-location/6832/1).