My obvious question although it doesnt help you - is didnt you have a ride before you bought it?!
That aside - Ive not owned a radier 16, but a good mate has one and Ive fished from her many times. I wouldnt say the ride was hard, not as hard as a full catherdral hull, but as she has a gullwing hull (a half way house between a V and trihull / catherdral) a raider 16 will slap and bang a bit.
My other point is that she is only 16' but feels bigger, so dont expect the ride of a bigger vessel.
Finally - if youre used to ribs, almost anything will feel hard - they are very, very soft riding.
Your set-up sounds fine to me.
Adam