When you buy an ARF or kit, the instructions tell you where the designer found the CG worked the best. Or sometimes, where he figured it would be best for a less experienced flyer. That designer knows how effective the elevator (stabilizer) is when setup with the throws he found worked best, and that's usually the suggested location you find in the last couple of pages of the included instructions.

So you wind up with two CG locations, the one suggested and the result of your components and your placement of them.

Its sensible to setup the elevator throws suggested as they match up with the CG location suggested, which matches those throws.

So are you afraid the plane will be too much to handle without some insurance? Just about all transmitters nowadays have dual rates. Use them, at least on the elevator. Setup a low rate that's about 2/3 the suggested throw in the instructions. Take off with the suggested throws and if it scares you, flip to low. Too much for your flying skills? Take off on low rates then. If it's too sluggish (like it'll be if nose heavy) you can easily flip to the suggested rate.

If both these ideas scare you, it'd be a really good idea to get an experienced flyer to maiden your plane for you.

Know the old saying, "a nose heavy model flies sluggishly, a tail heavy model flies....(fill in your favorite type of doom)"... really is silly, because anyone who would blow off setting a realistic CG and winds up taking off with a tail heavy model should take up a hobby better suited to them.