When it comes to recasting a part, there's more than one approach. In the Star Trek 2009 film, compare what they did with Kirk (Chris Pine, somebody who basically bore no resemblance to William Shatner at all, picked just for the kind of character they wanted to have rather than any comparison) versus what they did with McCoy (Karl Urban, ties his damnedest to do a close DeForest Kelley impression, even when he has terrible lines to deliver like "space is death and disease, wrapped up in darkness and silence").
There was a similar deal with Stargate SG-1, where Richard Dean Anderson bore no resemblance to Kurt Russell as Jack O'Neil(l), but Michael Shanks was selected to replace James Spader because he could do a great impression of James Spader's take on the character of Daniel Jackson.
With Han I think they're trying to go somewhere in the middle. He doesn't look or sound much like Harrison Ford (His face is totally different and his voice is higher), but they're trying to dress him up for the part, give him (sort of) the 1977 Harrison Ford hairdo, and presumably want to keep the character much more consistent with past characterization, as opposed to Kirk (who was a ground-up rewrite with no similarity except to the most flanderized memes about the character) or O'Neill (who retained his backstory but started acting very differently from the get-go). They don't want an impersonator but they want to fill the shoes anyway, and that's kind of a tricky balance. I dunno how it'll work out.
Speaking of Kirk, contrast Vic Mognogna- who even looks a little like William Shatner- doing a thorough Shatner impression in the fan show Star Trek Continues, and compare James Cawley's in-between performance on New Voyages/Phase II; Cawley doesn't look like Shatner at all, but he tried to keep the same sort of tone of the character. In other words, I think this guy is doing it sort of like James Cawley, trying to match the original's tone despite being obviously different.
It's a weird new approach for Star Wars, because Ewan McGregor was much more trying to imitate Sir Alec Guinness (and has explicitly said so), and I assume the same goes for Genevieve O'Reilly playing Mon Mothma in RotS (in a deleted scene) and Rogue One. Historically Star Wars tries to stick to it's own aesthetic, so having Han and Lando look as different as they do here seems... odd. The music tone seems to go with that too, with it's sort of 'buzzy' sound and comedy beat timing of the trailer. It seems they're experimenting with his one.
As far as the beginning of Solo's backstory in the EU, I thought they established he was a 10 year old thief who got captured by slavers, but not much more than that, right?
Also, one thing that always seemed odd to me about Han being in the Imperial Academy was how he has seemingly no idea how to handle the radio protocol on the Death Star in Episode IV. "We're all fine, here, now, how are you? *cringe*", boring conversation anyway, etc. I wonder if in this movie, maybe he didn't get far enough to learn that kind of thing? For that matter, I wonder how much they'll tell us about the Imperial Academy. Presumably Tie Fighter pilots come from there after they stopped using clones, and we know that's where Biggs went before he defected, and where Luke wanted to go if not for Uncle Owen constantly putting it off in favor of keeping Luke on the moisture farm. But we never really saw anything about the academy until now, except probably in EU works.
Edited by Mitsukara, 05 February 2018 - 12:42 PM.