Hi navpi,
I work at Airbus Broughton and can tell you the Beluga timings vary from day to day and can sometimes change last minute so it's a case of if your in the right area near Chester/North East Wales you will see it. As for the BMI shuttles, these operate Mon-Fri but the times have recently changed and some of the flights now operate directly to Toulouse rather than stopping at Bristol.
I expect the A350 to make another appearance before the end of the year and maybe an A320neo!!
Hope is is useful!!