Yeah, DS9 doesn't start to get really good until like Season 4-7.
Honestly, you could just skip everything and just watch all episodes related to the main story arc. There are lists out there that have the relevant episodes in it. Unlike Enterprise and Voyager, this series actually had decent character development and truly expansive stories.
It was a nice movie, but contains very little of what, in my opinion, makes Star Trek special. It has too much action; not enough science and discussion. But this goes for most previous Star Trek movies as well. The tv series is really where the franchise shines, especially in The Next Generation and Deep Space Nine. I never cared much for The Original Series to be honest.
The name makes complete sense to me. They present the Xbox as the one media system you will need at home. So 'One' makes perfect sense. If you want to rage about something, rage about the online requirement and the shitty mandatory Kinect.
For me DKC is special for mostly nostalgic reasons, but also the unique art style it had and the pre rendered 3D-ish graphics that looked amazing. Now it looks like just another platformer to me. Still, it's probably a very decent one.