Is it possible to commute to Everett, Washington for work from Seattle?

You will ideally need a car, but that is quite feasible. I'm sure many people in Everett work in Seattle, and you would likely be going against the traffic. I know there is a Swift Bus, and the Sounder Commuter train that goes into the train and bus depot in north Everett, but you would have to look into schedules to know how feasible your commute would be. Boeing and the jobs around there are more to the southwest part of the city.

Oh, and I grew up in south Everett. Nice suburbs around there. The north end is more sketchy, but not horrific. Areas to avoid: Casino Road, Broadway, Highway 99 (though that is somewhat variable).

It's not really practical to use mass transit to go from "Seattle" to Everett.

The public transportation for Seattle is really for King County.  Everett is in Snohomish County.  Depending on where you live in Seattle it will be a long trip involving at least one if not many transfers.   

Where to live depends on what kind of lifestyle you want to have.  If I had my choice I'd live on a houseboat on Lake Union, but commuting from there to Everett would be mind numbing.

Yes, it's possible. Whether the time it takes is worth it to you, I can't say. Google maps says the driving time from Everett to Seattle is about half an hour and so it may be, except in rush hour. I myself have spent a good solid hour getting from Edmonds/Lynnwood to Everett in late afternoon traffic, and that's only half as far as Seattle to Everett.

There's a bus service, quite frequent, with travel times varying through the day but it looks like a minimum of 40 minutes and that's for the times when it's an express bus. 

https://www.communitytransit.org/busservice/schedu...

Everett is as safe as anywhere else in the general area. If you are okay with living in Seattle, I don't know why you'd worry about the safety of working or living in Everett.

Everett is a suburb of Seattle.

If you want to live in Seattle and work in Everett... it's feasible.

But you are going to need to get a car.  Seattle isn't really a walkable city.