Carina will be good in the RedCat as it's nice and big. As for Cent A that is another matter. Yes it is large as galaxies go but with the RedCats wide fov it may not look much more than a smudge.
You might want to head over to the following website
www.telescopius.com It will let you set up your equipment and show you what a given target will look like with your setup.
As for the mount......hmmmm there's 2 camps with the Star Adventurer. Those who love it and those (like me) who think you'd be better off getting an inexpensive but quality goto.
Rene