Here are some thoughts - albeit a bit scattered -
In a musical, you have music v acting rehearsals, and the chorus v the leads - it is up to the music director to schedule and rehearse the orchestra (or band) in their own time - you actually don't have to deal w that until they move into the theater. But you want to find time for what's called a sitzprobe, which is where the orchestra and singers work in their respective spaces, going number to number, without any other pieces.
You need to factor choreography into the mix, which is a big chunk of your rehearsal time (esp if you are working w nondancers or "moves well" actors)
You can usually schedule concurrent rehearsals in separate spaces early on for chorus and principles because they often aren't on stage at the same time, so the chorus works music or choreography while the director works w the leads, and vice versa. It's best if they can afford a rehearsal accompaniest so you can have music in both rooms. And even if it's a show without a chorus, you will need to add in rehearsals where the performers sit with the musical director and learn the songs.
This is an area where having an assistant is essential - you can each be in a rehearsal room keeping an eye on things.
And for big group scenes, we sometimes split up taking blocking notes as leads v chorus, or SL v SR, depending on the nature of the blocking. Also, some songs are blocked and some are choreographed - so you want a dance captain who tracks all the movements of the chorus (and is responsible for keeping the dances correct and clean) - that takes one thing off your plate (tho you still need to have some sense of where everyone goes and what they do)
Unlike legit plays where you can buy a copy easily and simply keep it, you often have to collect the rented scripts and scores at the close of a musical and send them back to the company holding the rights.
You also have to add in piano-tuning time, tho how often will vary depending on how hard the instrument is worked and if you are sitting or touring. The tuner needs a couple of hours of relative quiet and can overlap lighting tech work, but the incessant pitch adjustments can drive folks crazy. And the piano will need to be tuned several times during a run.
You always need a call at a new theater to re-space and to hear the room, but that isn't different from a straight play.
Yes, there often are more cues. What I love is that you never have time to get bored in a musical - altho I gotta warn you, straight plays can have just as many wild and crazy and complex technical aspects. And you want a whole lotta batteries for the sound packs (tho that is usually the sound person's bailiwick)
There can be more backstage people, or less, again totally show-dependant. My two fastest quickchanges, both requiring dressers, have been with PHANTOM (a musical) and THE REAL THING (a straight play).
There is more but I think I will stop here to collect my thoughts (I just opened a complex and challenging show and my brain needs a rest!)