Yes and no. Honestly. It can be hard, there are characters always out, and some lines are long - like darth vader is long all day. The other thing is that most of the lines have different characters at different times - for example, boba fett and jango fett. So somebody might get in line with boba fett at the front, and it be jango fett when they get there. I know we saw commander cody 3 times before I finally just started letting people in front of us until we got captain rex. The line right at the star tours cue has luke, leia, r2-d2, and c3po. That line is usually long and they alternate, so you might get one or you might get two by the time you get up there. Some characters just "roam" so you have to go get them - there are three main "areas," in one jawas sort of roam, in another clone troopers roam, in the dark side area you might see tuskan raiders or storm troopers roaming. For example, Aura sing is a "roamer" in the dark side area, so you just catch her when she's out. Some of them aren't out for long, for example, with the jedi masters, kitt fisto is only out for maybe like 5 minutes (Florida heat). One line that can be sort of long is the disney characters in star wars costumes. Well, the line is probably only 15-30 minutes, depending on the time and the day, but it is one of those lines where you may get in line for Minnie and it will be Goofy when you get to the front. So, you have to get a feel for timing or get lucky or just let people in front of you if you want them all. Chewbacca can have a very long line and you have to kind of figure out the rhythm to "time it" because you may have to get in line while he is out now, to be able to see him the next time he comes out after a break. To make that more complicated, in the afternoons he is with an ewok, and they alternate between whicket and lokrai - like one session will be one, then a break, and it will be another when they come back. So if you want a certain combination, you have to time it right.
So yes, and no. If you just want to see "Some" star wars characters, then it isn't hard at all. Storm troopers, the cantina band, jawas, etc., are just walking around. If you want to see a certain character, it may be easy or it may be a longer line. Like if you want vader, just go get it line, its not going to get any better. But he's going to be there all day. Others you have to time. The cast members have paper schedules that they can look at to tell you if a certain character will be out at a certain time - some are really happy to look at it and tell you, others will act like it is a matter of national security and pretend that such a paper doesn't exist, even if you see it in their hands. Who knows why. It is summer in central florida and it can be hot. If you get in the longest line at the busiest time of day it will be horrible, if you get in a shorter line at a not busy time it won't be anything. You know? Your mileage may vary.
I don't think most families would be able to see all the characters in a single day and still be able to talk to each other when they left, if it is possible at all. Honestly I don't think it would be possible at all. But if you are happy to take it as it comes and enjoy bumping in to who you bump into without a quota or list, you'll have a blast.
If your kids like star wars I wouldn't hesitate to take them for one second. It is a lot of fun.
Oh here's the thing. C-3po can look at you and can carry on a conversation with you. You can look Chewbacca right in the eye and he'll wookie grunt. Clone troopers and storm troopers are right there in real life. You really have to go see it.