Small-field/Indoor positioning

[RefIADad]

I'm hoping that this group, with more games done with a single referee, will be helpful with some of my questions.

Over the past 3-4 weeks, I've worked two indoor tournaments. The field is basically 1/4 the size of a regulation field (about 55 yards x 30 yards). U14s and younger play 7v7 (6 and a keeper), U15 and up play 6v6 (5 and a keeper). Offside is not called in these games. We work as solo referees for these games. After doing some of these games, I've learned (sometimes the hard way) that I need some guidance on my positioning.

1. The first just deals with general positioning. First of all, I do run in these games. I probably run too much. My general idea is to have as much of the field in my vision as I can, which means if the ball is swung sideline to sideline then I will work my way to the sideline where the ball came. I'm trying to get the right angle more than being close to play, but I don't always succeed. For those of you who do indoor, where on the spectrum between "standing at the center line" and "running all over the field" do you try to fall?
2. This is more specific to corner kicks. In a game I did, I missed a takedown in the area because I was positioned close to the goal line so I could see a corner kick go over the line and then come back in (which did happen earlier in this game). As soon as I knew the ball wasn't going out, I did try to swing back to the top of the area. But as I focused on the landing area, the takedown happened off the ball and I missed it. The coach of the team was understanding about it (he specifically said "You're only one person - you can't see everything, and you can't call that unless you're sure you saw it"), but I still was pretty upset about it. If I was positioned at my usual spot in a diagonal system (usually at the intersection of the D and the penalty area away from my AR), there's no doubt that I would have spotted this.
3. With a diagonal system, I usually do a good job of keeping my eyes on the player who has released the ball to make sure I see anything late. In these games with fast movement and quick passing, I feel myself starting to focus on the next phase of play and sometimes missing late items. How do you balance this when you're on your own?

I know that working as a solo referee means you can't see everything, but I want to make sure I'm focusing on the most important items and learning to be OK with the less important things.