Yes, the included phone holder makes this camera tripod for iPhone convenient for stable photos and videos.

Yes, the tripod legs can be adjusted in length and angle as needed to adapt to various terrains, including uneven ground and steps.

Yes most definitely. This tripod allows a lot of heights and multi directions

The central post does not pivot, so the answer is pretty much no. That said, the ball head does have a slot to allow for portrait orientation. You can turn the camera downwards and achieve a straight down shot, but the legs of the tripod may not work well for this and you may get some of the post.

That's how I used it. I put it on a table and shot overhead video. So yes you can.