Widger,
I take the credit from no one!
It has been known for LACC to give the odd short cut. Sometimes this involves being outside controlled airspce. An example of this would be either a EGGD dep to the north routeing to NOKIN which, if turned early enough, goes outside, underneath UN862.
Now, it could be said that that's a join, (even though it goes past the join fix BCN or TALGA) so how about routeing a EGGD or EGFF from AMMAN to VATRY. This is a Ryanair special but they can't accept a RIS. So, if they want to got that way (it's down to the controller and his workload, as discussed before) you have to give them a RAS. That's not joiner or wx avoider.
To answer your question. I change the service whenever I have to.
I also said that L18 availability is published by NOTAM. This changes from day to day. The military sometimes like to occupy the NWMTA later on in to the evening.
P18 - I don't know.
The LARS units I work with are, without a doubt, first rate. They've helped me out many, many times. I hope that I can help them out too, when the time comes. At the end of the day, we're all on the same team trying to get the job done.
Regards
CF