How to trigger pressure plates from a distance

So here's what I know you can do (name followed by the quest you should start but not complete):

People

• Any normal follower (or, hey, Aranea Ienith can summon an atronach)
• Delphine + Esbern - Alduin's Wall (Esbern can summon an atronach)
• Brother Verulus - The Taste of Death
• Mercer Frey - Speaking with Silence
• Thonnir - Laid to Rest
• Avulstein Grey-Mane + Geirlund + Vidrald - Missing in Action (the latter two should join you and Avulstein at Northwatch Keep)

Animals

• Meeko (Meeko's Shack) or Stray Dog (random encounter)
• Barbas - A Daedra's Best Friend
• Horse (better yet, Shadowmere)

Summons

• Two summons (with 100 in Conjuration and the Twin Souls perk). Some dead thralls can summon atronaches, so that gives your summons one summon apiece.

which brings the total to you, nine people, two dogs, a horse, two dead thralls and four atronaches. That's 13 permanent and almost everywhere (excluding atronaches and the horse) and 18 potential. This seems pretty hypothetical and I haven't done it myself, so feel free to correct me.

Other

There's also supposedly a glitch (patch status unknown) where you can dismiss your follower, hire someone else, then immediately return to your follower and rehire him or her. I don't know if people use it with the Dark Brotherhood Initiate(s) for a reason or because it only works with them.

Also Odahviing.

Checking the Creation Kit, there is an item with editor ID "dunJaphetsFollyCWCatapultAmmo" and item ID 961D6. So you can give yourself 10,000 of these arrows and equip them with these commands:

player.additem 961d6 10000
player.equipitem 961d6

The arrows are invisible except when they're in flight, and they have no name in the game, but they work. You can't see the arrows in your inventory, so you either have to carry no other arrows or use the console to equip them.

On the subject of unusual ammo types, you may also be interested in item ID 73FE6: "CWCatapultAmmo." It's like the Japhet's Folly ammo but spreads fire where it lands. My guess is that this ammo type is used for the catapults during the Civil War.

(I wasn't able to catch the arrows by getting hit with them during the quest. Perhaps the Unofficial Skyrim Patch prevents the arrows from entering your inventory when you're hit with them—I don't know.)