Ah Ok then
Its nice and simple to place things in the editor. Open up the Generic Browser. On the top of that you should see some tabs. Go to the tab called "Actor Classes". Then depending on what you subclassed (I.E a Navigation Point) you will need to go and click the + Next to the parents name, then work your way down until you find your Actor. Once you have, click on it so it is highlighted.
Minimize that and go back into the main viewport. Right click where you will want your actor to be (make sure you right click on something besides the black nothingness) and then it will come up with a little window. Go down on that window until you see Add Actor then your actor's name (Ex: Add Actor UTWeaponFactory). Then your actor will be placed within the map.
You should then see it in your map at be able to test it out. Although to be 100% sure I would load up UT3 and play it within there if you encounter bugs.
For Default Weapons you can specify that within code in the Pawn class.
Also if you update your code, the map will use the new version so theres no worries about having to replace the actor after you update.