I do not have a lot of answers to your questions but I would not hesitate to buy Red Sea equipment. Heck, I don't even know what Reefbeat is but Red Sea has been making good stuff for a while now. They did have some seam issues on larger tanks that someone else may be able to speak to but everyone I know that had an issue was taken care of by Red Sea. (Not to say it wasn't a giant problem).
When I evaluate equipment, I'm looking for 2 things. First, good quality. By good I really mean good. i.e. it works and doesn't cost an arm and a leg. There are better options for nearly every piece of equipment I own but there are a whole lot worse options too. I'm a middle of the road on quality, or the most part. Second, I look at how popular the specific brand/model is. If a lot of people own it that usually means there's a lot of information available and repair/upgrade parts are available.
With that in mind, I look at Red Sea as a great option. Very popular, lots of repair/replacement parts available and tons of aftermarket upgrades that you can find on the internet. I apply the same criteria to a controller like Apex. It's by far and away the most popular and there are a LOT of folks on here that know tons about them. If I need help, there are probably forum posts about my exact issue.