Maybe some moves are just meant to be unsafe?
I obviously haven't played it so I don't know but if some moves come with lag then that doesn't sound too bad.. It just means those are situational moves Ala some moves in street fighter and games like that.
I mean, yes, it's expected that some moves aren't supposed to be 100% safe but a lot of moves that you'd expect to not have a crap ton of landing lag actually do. Sonic's back air, for example, looks like it has even slightly more landing lag than it did in Brawl (which it already had a good amount of landing lag to be punishable on whiff and shields). It just makes for a less offensive game because you have
less offensive options to work with for many characters.
That's why Meta Knight was super popular and successful in Brawl because he could play both offensive
and defensive. He had both options because 99% of his moves were quick and had no landing lag/barely any endlag -- allowing him to get away with a lot, even "combo" to some extent (in a game where no other character can actually combo), and control the pace of the match. On top of that, he had several stupid moves (tornado being one of the major ones).
Sheik is looking a lot like Meta Knight with the amount of options she has compared to other characters at the moment. Of course, that can change but I won't be surprised (if everyone else stays the same) if she and characters like her (such as ZSS) are the most popular character choice early on in the metagame.
Hopefully the game
does change by the time it releases but I'm not holding my breath -- there's been no precedent that Sakurai or his development team will listen to outside feedback from people pre-release.
Edit: Also, I'm glad swimming is gone.