Sal,
20 degrees should give about 8.6mm bevel. Based on your design spec of a 29mm depth of blade, thats what.......just under a third of the blade ground to a bevel. Of course it is 3mm rather than the 3.5mm you originally wanted. For me, thats not excessively fine, But I do prefer a "precise" blade. 58rc seems in the usual range so no worries there. I guess for me now, its going to be a question of edge retention, chipping and rolling of the fine edge.
I guess it wants to be used on some hard carving use, maybe jointing some fair sized bones and pehaps boring into a hard but knotty surface. If it takes all of that without damaging the edge and point, should be fine for me
Red