There are several broad swords, yes. Some characters that have these include:

Awakening - Flavia, Morgan, Gaius

Shadow Dragon - Nabarl, Marth, Oguma (this guy had the biggest sword out of anyone I saw)

Here's a pic of Oguma for reference:

So looking at the trailer again, I just noticed something massive.

Remember in the first trailer when Itsuki attacks the cloaked man with that ball of light?

That man is Chrom. In this trailer, more of that scene is revealed, and his cloak starts to disintegrate, revealing what is clearly Mirage Chrom's armor. Also, you can see him try to attack Itsuki with his sword arm. I always thought it was him since the first trailer because of his eyes, but this confirms it. This means that the figures in cloaks could all be mirages/"demon's" from Fire Emblem.

Watching it again with this in mind, you can tell that the woman choking Tsubasa is also a Mirage. Tsubasa's mirage, Caeda. You can see by her hand that she has the same exact armored gauntlet. Since this is presumably the beginning of the game, this is likely where they first meet.

Watching the trailer more, the ball of light that Itsuki uses to attack Chrom shines in just chest, then Tsubasa narrates the word "Performa," and then it cuts again to Itsuki finally slamming Chrom with this ball of light. This makes it obvious that this ball of light is Performa, and that Itsuki uses it to form a connection with Chrom. We see that Tsubasa also has an immense light glowing from her chest in the same scene. Since both Chrom and Caeda are shown later on friendly, but clearly in the same area, it's safe to assume that both Itsuki and Tsubasa "purify" their mirages and awaken their Performa at the same time, during this whole ordeal.

Itsuki awakens his first though, as there is a scene with a purified Chrom, but Tsubasa is still being choked in the background by the cloaked Caeda. I assume he purifies Chrom with his performa, they fend off some of the monsters in the hoods, and then Tsubasa awakens her performa and purifies Caeda.

Strangely enough, it is in this room that they first enter their Carnage forms in this room, as the trailer shows them both in this room getting ready to fend off more enemies.

Also, the guy in the yellow suit interviewing Tsubasa right before things go to shit is this guy:

Which probably means he's the first boss of the game after you purify Chrom and Caeda.. It also probably means that the demons or whatever can corrupt human beings and even turn them into monsters. Assumedly if their performa isn't powerful enough to protect them.

Marth is pretty popular. I can see him getting Marth.

With Shiida and Chrom being main characters I see Marth and Lucina being last bosses/secret bosses . 

The class symbol looks like mercenary/hero , I would say it is Ogma too .