If you really want to get scientific, it's actually nearly impossible for humanoid species to exist on other worlds. We are the result of billions of years of evolution in reaction to specific events on our planet. See this:
I dunno if I'd say nearly impossible. There was a lot of parallel evolution in Earth history. For example, just about anything which swims through water, due to physics, is going to look a lot like a fish. One can argue things like bilateral symmetry and a front/back end are highly likely. Thus a 'head" is also likely, which will contain most of the sensory organs. The species will likely need limbs for both locomotion and tool manipulation. As a result, even if you don't get a humanoid, you would get something which would be roughly comprehensible most of the time.
Of course, there's an in-universe explanation which is given in Trek - the ancient humanoids. Honestly if I were rebooting Trek, I'd go one further and explain that the Iconians took ancient humans off the earth and genetically modified them and spread them across the galaxy through their gateway system. It would help toe explain how humans can interbreed with virtually any humanoid alien race.
Aside from budgetary concerns (alien aliens would have to be entirely done via CGI or puppetry) there is an additional issue in terms of execution. Basically, if you make aliens realistically alien, they stop being "characters" as we understand them, and become something more akin to plot devices. Written sci-fi can get around this because some of the plot can be from the POV of the aliens, allowing us a view into their internal mindset, but this would be difficult to accomplish on screen.
Fuller was the one who decided to have familiar races redesigned though.
All we really know is Fuller insisted the Klingons be bald before he left. They might have made the makeup redesign more elaborate - and applied it to all Klingon houses - after he left.
Also IIRC, the anthology idea was meant to follow a different crew each season, not the discovery
Sort of. The idea was Season 2 would introduce the new cast, have the show flip back and forth between the two crews for the first 3-5 episodes, and then switch over exclusively to the new crew.
We're not going to save the planet, the galaxy, or the universe. We're going to save... the multiverse!! When they basically said this, it was so disappointing. Telling a story that large with such far reaching consequences for failure meant ultimate success from the jump, for one, for another it never had to be such a large ante to begin with. A small story set in that time period in the lead up to TOS could've been amazing.
Yeah. As I said before, the show was seriously thematically muddled in general. It had these ambitions of telling this quadrant-spanning story. Yet what was shown to us onscreen was extremely confined. We were supposed to be following the arc of the entire Klingon War, but basically only had four "named Klingons" introduced across the entire series. The same six guest stars kept popping up again and again, and all of the major aspects of the arc implausibly revolved around them. The Discovery felt like an empty ship, and the crew barely ever got a chance to go anywhere which felt densely populated. I think a lot of this was budget-related, but it meant that the overall structure - which was honestly rather like a stage play - was very ill suited for the epicness they had aspirations to achieve. A "small bore" plot focusing on the personal redemption of Burnham would have been much better shorn from the whole saving the multiverse, being personally "responsible" for the Klingon War, etc.
. I want a post-Voyager series because I liked that era, because it offers a rich array (sorry) of possibilities, and because it frees potential doofus showrunners from the technogap and canon transgressions. Also, that time in ST may have needed some rest 17 years ago, but now it's prequels and reboots that require a nap. Stat. 
And wait - why in the heck did you like DISC again? 
