Coolie- I seem to recall from my training days that even 180kts was too fast to achieve a Rate 1 turn at 25 degree bank. I may well be wrong, but I thought I'd left Rate 1s behind with the Cherokee. It was rather a long time ago!
Do you know where can I find some rules on how to perform interceptions ?
You're going to get as many different opinions as people answer! I would suggest this- flying procedures should be at minimum flaps up speed until you start thinking about approach. This means something like 230 kts on a 747 and 210 kts 737. 250 is too fast- turns far too big. The small increase makes a big difference. In holds in a light aeroplane, I remember as you were coming around to the inbound course, at 90,60,30 degrees to go, we used to look for lead to inbound course of something like 25,15,5 degrees to go, allowing for wind- I can't remember the exact numbers. That was under very precise training. Now I feel KISS (keep it simple, stupid). I find trying to do fancy mental calculations in your head whilst trying to align onto a course too complicated- you can easily turn the wrong way or mistake the right track. Just make an estimation of turn radius/wind effects, see how it works out and use that to alter the next time around. Turn radius doesn't really help you when you are looking at an ADF needle.