First off - there's two vastly different Lightning Archon builds - Those with Obsidian Ring and those without - which uses Convention of Elements, which seems like that's the one you are using according to the D3planner.
You don't use Arcane Torrent because you aren't using Obsidian to shorten the cool down. That's why you use Magic Missile - it doesn't use arcane mana.
You want as high of a Cool Down Rate aiming for around 64% to cycle with Convention of Elements - need to pop archon to time with the rotation of Lightning.
Paralysis procs with Manald Heal more if you have high Attack Speed. So with Gogok of Swiftness and Archon stacks you want to aim for 5 aps. Unbuffed you should have it close to 2.0 if not higher.
Starfire is better than The Furnace - because of all the lightning attacks you are using. You want your bracers to have the highest elemental damage out of everything - so that's what the element is used while in Archon form.
So - you are pretty much teleporting (Arcane) around - why you use Aether Walkers - and casting Magic Missile (Cold). When Archon is ready to pop - use Black Hole - Spellsteal (Lightning) to group as many enemies as possible (more damage stacks) - then cast Archon (Fire). With all 4 elements cast the Tal Rasha set will be giving you a huge damage boost. All the while timing the rotation of elements via Convention of Elements.
So the stacks - Tal Rasha, Black Hole, Archon and Manald Heal all add up to the HUGE DAMAGE OUTPUT.
However, you are sacrificing speed for the power.
Using the Obsidian ring - you are in Archon form 99% of the time, while COE you have to time everything precisely and only have that huge damage output for like 8 seconds.
IMO - I use the Obsidian builds until I get all the perfect pieces to finally run the COE build. COE sucks balls if it isn't perfect - Max CDR on all gear is a must because if that doesn't synch up you may as well just play another game
Manald Heal procs with Paralysis. To get that damage more frequently you need high Attack Speed.
Arcane Torrent - is a mana spender. That speeds up the Obsidian ring.
Have Lightning attack % on your bracers. Make sure that is your highest elemental damage, as that's the element that will be used when you are in Archon form.
Your 3 RINGS - Obsidian Ring of the Zodiac, Ring of Royal Grandeur, and Manald Heal. THOSE ARE A MUST.... Equip 2 and Cube the Other. For Manald Heal to work you need to have Paralysis as a passive ability.
Yes, Plan B - that's what you want. Not the one from D3planner as that is the COE build. You are no way near to doing that yet.
Just note that IcyVeins build is for speedrunning. There's a few things you can change to make it for pushing higher GRs. But don't worry about that yet.
You want to try to get Attack% and CDR on as much of the gear as you can. And lightning % on your bracers.
All your lightning damage while in archon form comes from your bracers. All your lightning damage while out of archon form comes from Arcane Torrent. But when you are out of Archon all you are trying to do is go back into archon. Arcane Torrent is mainly used for the elemental damage and as a mana spender to speed up the Obsidian ring for CDR.
Also note, the first time you start the rift - you'll be using Arcane Torrent's attack as a way to build up the Gogok stacks. You don't necessarily need to get it to 15 before you pop Archon, but it is good to get a few as that adds to your attack speed.
It won't be until your 2nd or 3rd time you go into Archon when you get the full effect. Keep checking and notice when your attack speed goes to 5. Pretty much when Gogok stack is at 15 and your Archon stacks are doubled up (with the help of The Swami).
Heres an an updated video for Season 11. Its the exact same setup as IcyVeins speed running build.
Aether walker is is used to teleport when out of Archon form. While in archon, its the 2 piece set bonus of Vyr's that allows you to teleport at will.
The high CDR is so you can get back into Archon form ASAP. Notice in the video I spend less than a few seconds out of Archon. This also helps because of In-Geom proc. You want to kill elites and mob bosses as much as you can, that's why Nemesis Bracers are a big plus as they will spawn one when you activate it. There's one instance where I didn't kill one and you can see I'm out of Archon for a lot longer.