I consider myself the Superfriends connoisseur and I enjoy the many flavors you can get from them.
One of the boons of walker decks is that you can chop and change between them to get a different experience as time goes on.
Ghostly Prison,
Propaganda,
Forcefield,
Blazing Archon don't actually help to protect your planeswalkers. These are easy cuts.
Inexorable Tide is too slow and inefficient. Been there, done that.
Fuel for the Cause same deal.
Contagion Engine is pretty slow as well.
Deploy the Gatewatch has a 41% chance of hitting 1 planeswalker and 18% chance to hit 2 of them. So it really isn't very consistent given the number of walkers you have.
Just in general when quite a large part of the game plan is to resolve a creature sweeper and then follow that up with a planeswalker(s), keeping your creatures at a minimal can be beneficial.
For example rather than
Birds of Paradise you can play like
Wild Growth or even
Utopia Sprawl as you have access to all the good lands.
Lighthouse Chronologist,
Old Man of the Sea,
Hanna, Ship's Navigator all fall in the category of not really good enough given wanting to cast creature sweepers often.
Elesh Norn, Grand Cenobite might as well be a cheaper creature sweeper given that you don't have ways to cheat it out.
Shalai, Voice of Plenty protecting planewalkers isn't that great anyway as targeted removal isn't the biggest concern normally and you're just better off having a counterspell of some kind instead if protecting planeswalkers from targeted removal.
Swan Song and
Dispel are premium for this.
As far as additional mana sources I'd cut
Chromatic Lantern,
Gilded Lotus.
Technically I find Talismans better than Signets because you can use that extra mana on Turn 2.
Talisman of Curiosity,
Talisman of Progress,
Talisman of Unity.
Arcane Signet is of course the best of the 2 mana artifacts.
But again I'll bring up
Wild Growth,
Utopia Sprawl,
Fertile Ground as they are better with
Replenish and less likely to be destroyed or prevented with hate cards like
Collector Ouphe,
Null Rod, etc.
Play
Three Visits instead of
Cultivate.
Reliquary Tower is one of my biggest bug bears in all of commander. Please just trust me and replace it with a color producing land like
Rejuvenating Springs,
Yavimaya Coast or
Waterlogged Grove.
Spending 5 mana on
Ignite the Beacon you'd honestly just want to resolve a 5 mana (or less) planeswalker instead. It's just such an anti-tempo card.
Luminarch Ascension is actually pretty inconsistent having played with and against it many many times.
Extra turn cards are pretty nice in walker decks and although they are obnoxious to play against if you can find a slots for
Temporal Manipulation and
Time Warp.
A card that I'm huge on is
Mystic Sanctuary. Now in a 3 color deck it's pretty hard to run, however you do have all the good basic land type duels and fetches so is definitely worth considering. It is a really powerful tool to have when you've already cast say a
Supreme Verdict or
Terminus and then you can use a blue fetchland to get
Mystic Sanctuary to then cast it later on in the game for a clutch play.
It also goes infinite with
Venser, the Sojourner exiling
Mystic Sanctuary and putting
Capture of Jingzhou back on top for unlimited turns. Or just keep putting back a creature sweeper so that you can emblem
Venser, the Sojourner.
I'd replace
Interplanar Beacon with
Mystic Sanctuary as Beacon will trip you up on not fixing colors for the rest of your spells.
As far as the planeswalkers themselves you've got a great bunch. As I said one of the best things about Superfriends decks is that you'll get to chop and change to try out different ones to give it a bit of variety. The following are ones that
eventually you should give a try (imo).
Teferi, Master of Time - Activating planeswalkers in opponents turns is strangely very satisfying. Honestly one of the most fun moments in my playing experience has been a
Teferi, Temporal Archmage emblem. But Teferi, Master of Time gives you a little teaser of that.
Teferi, Time Raveler - Cheap walker with tempo and can be used to resolve a big spell.
Ajani Unyielding - Has supporting role of giving other planeswalkers ultimate potential and has card advantage and removal.
Jace, Architect of Thought - With
Doubling Season you can ult straight away and get another walker to ult AND get cards from opponents libraries which is hugely satisfying looking at all the juicy spells opponents have. Has card advantage and a certain level of protection with -1/0 at other times.
Garruk Wildspeaker - has always over-performed my expectations. The additional mana can be a huge factor in games, and the 3/3 Beasts can really protect it sometimes.
On a more focused theme you could look to leverage with
Estrid, the Masked and
Calix, Destiny's Hand with your relatively high enchantment count.