I'm not sure what you mean by "the blue lines are not complete". They are on my system, but...
Celestia only calculates 10 points around each closed orbit and essentially draws straignt lines between them. This is to minimize the amount of calculation that needs to be done between frames. More calculations = slower frame rates. If the orbiting body is not close to one of those 10 points, it can be quite a distance away from where Celestia draws the closest line. The position where the orbiting body is drawn is quite accurate, but the lines aren't. (I guess I should add this to the FAQ.)
I'm also not sure what you mean by a "red triangle in the circle". Do you mean the red Marker? That's usually a diamond, though, which indicates what object is Selected. Se the Users' FAQ at the top of this forum, Q&A #11 explain how to turn it off and on. (Control-K)
If typing a Control-K a few times doesn't turn off and on the red thing you're seeing, you'll have to provide a picture with circles and arrows and a paragraph on the back explaining ... Oh, sorry.... I got a little carried away
Does this help?