K00lDudE1 I'll comment on each of these cards...

Dovin Baan: looked great when I first saw him because he protects himself with the first ability and the ultimate is a Static Orb only for opponents. BUT I believe you can't play a planeswalker because of his ultimate (as you probably won't get to pull it off anyway unless you already control the whole table) and his 2nd ability isn't worth removing counters from him. Canceling creatures' activated abilities is done best by Cursed Totem, also Pithing Needle or Phyrexian Revoker if I want to have more similar effects, because they are all artifacts and can be cast easier, faster and also with Mishra's Workshop.

Narset Transcendent: tested in the very beginning of the deck - 2nd ability is useless here, first ability isn't a reliable card draw either...not playing her for the ultimate alone (besides, Jace, Unraveler of Secrets is much better imo, so he would be the first choice if I included another planeswalker)

Grand Abolisher: needs to be cast early to have an impact against control and with WW I can't reliably do that. I rather drop a Sphere of Resistance or Thorn of Amethyst instead...

Torrential Gearhulk: no targets in this deck

Cataclysmic Gearhulk: doesn't attack the lands and doesn't remove planeswalkers, so I rather go with the original Cataclysm. By reducing artifacts and enchantments to one I hurt myself much and if I don't take the lands with the same action I lose more than I win.

Tamiyo, the Moon Sage: to be considered for my 1 vs 1 tournament version of this deck (Augustin's $t4ks (tournament version)) because she can tap out mana artifacts (happened to me yesterday, it's pretty effective). Costs 5 mana and doesn't have a global effect, tapping one permanent is not often essential with more people on the table...2nd ability could potentially draw some cards but is it worth ? When enough tapped creatures are on the board from which Tamiyo could get cards, she will surely be killed in the next turn...not enough impact for multiplayer imo.

From these cards I would consider Dovin Baan for multiplayer and Grand Abolisher for one on one. Dovin Baan might indeed survive long enough with his first ability to get to the ultimate and then it's devastating. Grand Abolisher might improve the matchup against other control decks in 2 player games, but something without double white would be great...