Plants are reasonably resistant to chlorinated water, after all people water their lawns/plants from tap water with no issues, its just your filter and to a lesser extent your fish that will have issues. I would say that, provided you have no fish and no mature filter and no mature substrate you needn't bother with dechlorinator or heating, the chlorine will probably gas off or react with organics pretty quickly once in the tank.
However dechlorinator in form of Prime doesn't cost much so just add Prime to tank as it is filling.
As for heating the water, yes, as it stops your hands freezing off if you need to do plant fiddling. Plants just grow slower in colder water.