In the ticmic - Swiss Toni game, wouldn't 18 Bd2 have been a better way to block the pawn? You don't hem in that bishop, which you point out is a problem; and as a bonus, you attack b4.
White's b2 doesn't need protecting right then, and you can get the knight out some other way - if only through c1, temporarily putting a little bit of pressure on d3.
Yeah, 18.Bd2 looks better. 18.Nd2 and it looks like White had e3-e4 plans.
After looking at 100's of RHP games it's often you see short term ideas. (e3-e4) being
played. It's as if the player is happy to see something, an, idea and it does not appear
to hang anything. So they go with that and move quickly onto their next game.