Regarding the rules concerning eligibility of qualifying standards at domestic meetings and abroad I can imagine the thinking when they were set up went something like this:
Domestic meetings - I suppose they didn't want to be selecting athletes who only do their qualifying standard at an area or local league match, open meeting, minor representative match etc in front of 3 spectators and a dog. I can see their point with this as I can think of a few male throwers of the fairly recent past who definitely fell into this sort of category.
Meetings held abroad - Perhaps it was thought that top British athletes were only likely to compete or achieve standards at quite major meetings so it wasn't necessary to put in any similar restrictions. Obviously, this would appear to have been a rather naive judgement to say the least as British athletes do actually compete abroad at some quite minor meetings.