Every deck should have some Frodo protection beyond just a hobbit sword and adding the 2x Severed helps at just about any time.
Merrick, really thanks for your feedback. I will treat each point you mention...
This should be a Serie 2 deck, as Knights show up at set 5. As each Serie 1 deck has 2x
Severed His Bonds and 2x
Hobbit Sword, decks from further series don't need that addition... We can add them to the testing versions anyway, that's a good point.
New errand can save Frodo from swarming too!
IMO each deck from Serie 2 should have
1x or 2x Hobbit Sword, that way Serie 3 won't need any generic hobbit aid at all, allowing more card slots for themed synergies... A total of 3 Hobbits Swords are fairly enough for a non-hobbit theme like this one, so I'll cut one. Every free slot here is GOLD.

I dropped Armor and an Elendil's Valor. Anything that makes a companion Defender +1 is amazingly powerful in sealed. Tread with caution when using it. I want it to be more of an out in a bad situation than a major pump. To that end, I might also switch out the Gondor's Vengeance for dagger strikes so that you end up with 2x dagger strike, 1x Gondor's Vengeance as you have lots of hand weapons. This would also help clear the board if you are trying to set up the ability to double move.
Armor is there to survive Battleground/Site Control/Machine Uruks. As for the defender +1, you're absolutely right! 1x
Elendil's Valor should be enough, besides RB Rangers deck has one too. (I was going to add
I Will Go instead of it at the first draw...)
That leaves a total of 2 free slots...

I changed Merrys to give more flexibility in the starting lineup. If you get a sword early, you have another solid companion who isn't going to die early on. Also works well if we make the change to dagger strikes. I don't have a problem with Boromir, Steward's Heir or Knight's Mount. They seem pretty reasonable and low power additions to the format.
Learned Guide was there to prevent an early swarm and discard him when set up, but your point is better: if you want to reduce companions, just send a non-exhausted Merry to a 14 strength guy...
I'd consider pairing this with the Dunland Swarm deck. They seem somewhat complementary.
Well heard my fellow! This fellowship can handle Dunlendings given those fortifications,
Knights Mount and
New Errand, and they should complement well each other as the shadow empties hand quickly.
Boromir, Steward's Heir is pretty cool...at first I was kind of skeptical, but I agree that he's not overpowered in any way. Just adds some keywords that lets him bear possessions that Boromir usually doesn't bear 
Overall, the deck is a little sporadic though...it almost can't decide whether it's Knights or Rangers.
While having the Knight count too high might make the deck a little to easy to run the fortifications, you could always throw in Dervorin (replace Faramir) to work the same way as Gondor's Vengeance, while not being a knight and having a conditional ability so he's not too OP.
You could drop the two New Errands for something Knight related. Right now there are only 3 fortifications, another Citadel of the Stars would be too much, but First Level would be ok I think...There's a skirmish event for Knights that is essentially the comparable card to New Errand, wounding a minion bearing a fortification, I think.
EDIT:
3x War Must Be for 3x Swordarm of the White Tower
Dmaz, that Boromir not only can use more possessions/conditions, but events:
Gondor's Vengeance,
New Errand. The latter saves necks...
As for the 'sporadic' property, the idea is to use Boromir as a bridge between Knights and RB Rangers in order to make this deck give benefits to, or get benefits from, the RB Ranger deck from Serie 1... and to get some strange subtle dynamics too! But you're right, I'll charge it towards Knights: I'll use those 2 free slots for 2x
City Wall...
First Level is trash by itself, or overpowered with
Turgon.
In respect to transferring the fortifications for free, I think you are thinking about the dynamics of King Block's Knights: fortifications can be replayed with
Sixth Level, you can heal
Ingold twice, you can exhaust a minion with
Fifth Level, and then kill it with
Gondor Bow... Nothing of that applies here, so let them be free with 4 or 5 knights.
The event you refer is
Men of Numenor, but it wastes 2 card slots instead of 1 (the fortification and the event itself).
New Errand uses only 1 but has a condition: the minion must lose.
3x
War Must Be... Due to scarce fortifications,
Swordarm of the White Tower seemed better. Now with more fortifications I will exchange them. 2x
War Must Be and another
Might of Numenor, as those 5 fortifications are pumps too.
Really thank you guys for the feedback.