Re. Orville-
I am a bit disappointing, but I was expecting something much more comedic (not quite Family Guy in space, but definitely something along the lines of Galaxy Quest). That being said, I do not think it's a bad show. It has some solid VFX for what it is, and some of the stories have been fairly interesting. Overall though, I do find the 1 main running gag overdone and annoying. I find the characters all fall short of potential, and fairly under-developed. To me, it's not a bad time-killer if you have nothing else to do, or are between other shows. I do not find it something I would go out of my way for.
As too Character Development, this is always tricky on shows. Some shows nail it quickly, others linger for seasons and still grasp at stars. The original Star Trek, the characters were a bit shallow, and intentionally so - but focused on a couple of key aspects to make them unique and endearing to the audience. Firefly nailed it - just the interplay between the characters and their personalities is established right there in Episode 1, and from there it is about slowly delving into those characters and learning more about who they really are (or aren't as the case may be). I still regret having not given the show a chance in first run. Babylon 5, it was a mix - Some of the characters and their progression were epic from seasons 1-4 (G'kar and Londo I really loved watching them change slowly) while others started flat and were replaced often with other 2-dimensional people (sadly some that should have been main characters). I really enjoyed Star Trek The Next Generation and felt that most of the characters got good development over time, though slow in some cases, where-as I hated Voyager and no matter how many times I am forced to watch it only 2 characters ever really appeal to me at all and they are still two shallow overall. Right now, with Orville, it is just that none of the characters really hold my attention. Maybe they will develop some of them, only time will tell.
R.e A-list actors in Sci-Fi
If you have never seen it, I recommend finding Saturn 3. It is a lovely sci-fi thriller from 1980 featuring Kirk Douglas and Farah Fawcett. I feel it has always gotten poor reviews and unjustified low ratings. Another good one, where the sci-fi is more of a backdrop rather than the focus, is Outland, Starring Sean Connery.