I read through the reviews a bit, and the amount of people leaving 1 star reviews because the camera is above their skill level is amusing, and suggesting this camera is bad. It's user error, 100%, this camera works excellent in OBS with clean HDMI.
There's a really simple solution, read the manual.
1) yes, dummy batteries work, the rubber latch is also the door. Just lift it up instead of sliding it and the plug lines up, it's literally got a full image diagram on how to do this.
2) no, it doesn't charge by USB, it's a professional camera, not a webcam. Buy a few batteries if you need to use it away from a power source with the dummy battery. That's why they sell multiple battery slot chargers, that's what professional photographers do with professional cameras.
3) the software autosyncs to your computer and phone... If you read the manual, it tells you how step by step. In fact, you can choose between Bluetooth, wifi, or both.
Buy an SD card with a minimum 170mbps, Sandisk makes a bunch of them. I got the 170mbps 256gb, works great, and I can record over 4 hours of 4k footage to it.
I've literally never bought a professional camera before, so I did what any noob should, I read the manual and did research for about 2 weeks before choosing one and voila, now I know terminology, functions, settings, and can use the camera for streaming, photography, videos, OBS via HD60, etc...
If it's a bad review because of functions, it's very likely they didn't read the manual. Took me 3 hours to go through everything, and now I can operate the camera in a ton of different lighting conditions, environments, video use, streaming, whatever.
There's a term in tech, PEBKAM. It translates to 'Problem exists between keyboard and mouse'. Ultimately, it means the user is the problem, not the tech. I saw a bunch of 1 star reviews with a significant amount of upvotes, so these bad reviews are a problem. It's not the camera, the people who left the review didn't read how to use the camera. It's a shame, there's a lot of people that will overlook this beast of a camera just because someone that didn't read left a review. You read this, so kudos to you, you're better off than over 300 people that actually believed and found the 1 star reviews helpful.
This is an excellent camera for OBS if you use a capture card; I'm using the HD60 flawlessly, clean hdmi and all. While you can use USB, don't. It's just a feature they added for convenience, it's not going to be great quality on a USB connection.
Get a capture card if you want to use this as a webcam. It's a professional camera that has the added convenience of allowing a USB connection, not the other way around.
I highly recommend this camera; for the price point, you get a ton of features most other cameras don't have. If you are a camera noob like me, just read the manual, and use a search engine to look up terminology you don't understand. Within a few hours, you'll be able to use the camera to it's fullest extent; there's a learning curve, but also worth the time invested in studying. I'm getting excellent results, setting the correct ISO, using the proper lighting, etc.
If you are going for a blurry background with a focus on yourself, you might need a different lens. Don't get me wrong; this lens can do it a bit, probably enough for most people, but not okay if your subject is not very far away from the background to blur. If you don't know how to do this, search about aperture. Buy the camera with the default lens kit first, you'll likely buy the wrong thing if you don't understand the camera, lighting requirements, distance from camera/background. Read the manual, and look up all the terminology you don't understand first. Distance from background and lighting type makes a massive difference in which lens will be the correct to buy if you want an extremely blurry background with clear subject focus.
Is this camera for an amateur? No, not really. They did a great job explaining everything in their manual, and I got some additional help from YouTube, but here we are 24 hours after I opened the box, and now I'm pretty good at navigating it. I know what to look for in the settings for various lighting and distance scenarios because I read the manual.