I have to agree. I use silicone on both my nitros, but it's not regular fuel tube, it's 10mm od exhaust silicone. But fuel tube is a good way to start, as you can experiment with different lengths.
Distance between servo shaft and steering rod is around 30mm on mine, but don't be afraid to try longer or shorter. Double check the balljoint on the top triple is not stiff, this is a common problem and will interfere with proper setup.
Ok, which ever way you have the steering setup, you should be able to hold the bike and shake it from side to side and see the front wheel move side to side too, without much movement of the servo arm. If this is ok, turn your transmitter full left and make sure the wheel moves full right. Same with the other side. Also make sure the steering centers at the same point when you return to neutral.
Rake should be at maximum (all the way out) Only on short twisty tracks would you be tempted to decrease the rake a little, but the downside is stability suffers.
If you still get steering problems, remove the steering shock and try it, but don't go too fast without it!
The side protectors are only there to gauge maximum lean angle. You can buy new piano wire and make your own, try shorter ones for more lean angle, or bend them up a bit. If the bodywork scrapes the ground mid corner, you got the lean angle too far. Also if the surface is not so grippy, you may have to limit the lean angle by extending the bars or bending down.
If you try to turn hard while dragging the bars, the front will wash away and steering will be lost. The bike will appear to slide sideways. Best to try just lightly touching the bars in the corners, if you find they are dragging too much, a touch of opposite steering or applying a bit of power will lift the bike a little, allowing it then to complete the turn without excessive scraping.
HTH!

John