Never 3D printed before, what limitations should I take into consideration when designing in CAD?

As the title suggests, I've never 3D printed before, and although it intrigues me, my wallet cannot handle another expensive hobby.

With that said, I'm currently in the process of doing a mock-up in blender so I can get someone who actually knows what they're doing in CAD software to design me a case for my portable power station.

I don't know how advanced 3D printing is, and if there's any limitations to the prints so I figured this would be the best place to shoot my concept and see what others thing.

To start, I'm going to get it printed from an industrial printer, so I assume size isn't an issue, it won't be any bigger than 13"x13"x13"

The case won't be complex by any nature, just a flat case with rounded corners, which I know won't be a concern but I also want to have built in grab handles like you'd see on a plastic storage tote.

Inside the box I'm going to section it off. One second for my battery so it fits snug and can't bounce and shift around, one section for my inverter, and one for my battery chargers. Should I make these dividers a certain thickness? I'm afraid if I go to thin the print may struggle?

Is there any things I should keep in mind when designing a storage case design?

Obviously the lid and base will have to be two seperate peices. I intend to rivet in some hinges and latches.

Is there a certain thickness I should use for the case? Total weight of everything is probably close to the 50lbs mark, I'm not sure how brittle 3D prints can be, and the inside components ain't drop friendly nor are cheap. I also plan to mount a couple light things on the sidewall.

To screw down and secure my components I was going to initially make standoffs on the bottom of my case with threads to fit M4 bolts, but decided instead I'll make standoffs without any threads so I can just drill it out with a slightly smaller drill bit and then thread the bolt in carefully to make my own thread. I decided this because I'm unaware if my original idea is even possible to do not only in CAD software, but more so printing it. What's your thoughts on this?