Re riser weight... I've played a lot with that, since I'm a wood junkie and put as much effort into the selection of wood for looks as I do the bow
Rob's right that there isn't mass enough for a tremendous difference, but you can sure feel the difference there is. I've gone from the light end, bamboo and cherry risers, to katalox and Argentine Mesquite (not related to the US variety). These latter are right close to ebony.
Bamboozle and Cherry Pie are barely a pound. Arakhor, with the Arg. Mesquite, is 24 oz.
Just for kicks, I went down and weighed a bunch of bows, unless noted, all are 66":
Bamboozle, laminated bamboo riser - 17.5 oz
Arakhor, Arg. Mesquite - 24 oz
Cherry Pie, cherry riser and limbs - 16 oz.
Hill Robin Hood, Texas Ebony riser - 20 oz.
Hill Big Five by Craig, cocobolo riser - 19 oz. (68" bow)
Kramer Big Five, very slim 36#, walnut riser - 15 oz.
Howard's Golden Eagle, myrtle or maple - 22 oz. (68" bow)
So, you can definitely get an extra 6 or 7 oz. from the riser, and you definitely can feel it in handling the bow. I wish I still had Smoke on hand to weigh. I used a laminated katalox riser on that one and it really had a nice feel in the hand.
Cutout on Hills seems to run 3/16" to 1/4", but be careful, you'd be amazed how much difference the thickness of the leather makes! One reason I often just shoot off the wood.
RE arrows, I keep a set of Easton alum sizes from 1213 through 1916 bare shafts ready to shoot. (plus a few odd heavier ones I've picked up along the way in case someone who shoots heavier comes by). Just see which one shoots best, try it fletched, then make up a set, or, if wood is wanted, use wood of the same spine. Been using that set of bare shafts for years now. Great investment if you have a lot of bows coming and going.