I just made a holder out of 1" pvc pipe and tape newspaper to it with duct tape. You can build it for under $5 including a roll of tape. Cut the pvc so you have a 22" x 22" square at the top. I used 2 elbows and 2 tees and 2 5' sections of pipe. You need about 10'. I already had a base with rods for my 3D deer target. If you need to make the base as well, get 2 more tees and another 5' section of pipe. If you want to cap the ends of the base to keep it from rocking that would be okay.
Then tape a piece of newsprint to the frame as tight as you can without tearing it. Put it in front of a bag target for a backstop. Back up 10' or so and using your best form, shoot through the paper with a field point tipped arrow. You should have one hole with three slits coming off of it. You probably won't at first, but that is what you are trying for. If you have two holes or a hole and a tear, you will have to adjust point weight or spine (either by cutting or changing shafts). If your point hole is to the right of your fletching hole, you are stiff. If the point hole is to the left of the fletch hole (nock left) you are weak. Of course you may also need to adjust for nock high/low conditions, which will also show up on the paper.
Do a search here. I'm sure someone has done a better job explaining it, maybe with pictures. I know Rod Jenkins shows how on one of the Masters of the Bare Bow DVDs. I think it was III. I like the instant feedback without having to shoot dozens of shots.
I don't think you will need to trade them. You have some room for cutting and plenty of weights to try. I like 1916s or 2016s if I shoot aluminum. I most often use carbons these days though. I would think 400s would be quite stiff for the bow weight you are using. I have to have from 225 to 310 on my 28.5" 500s for my 46 to 50 pound bows.
I draw right at 28" and with a 28.5" shaft and a 50 grain brass insert, I draw the back of my broadhead to my index finger, kind of like an extra anchor or a silent clicker if you will.