I think Mr Maker knows something terrible about somebody high up in the BBC. How else does he get an all-expenses-paid holiday to Rio to do a kids' craft programme? Mind, he always says "Where in the world are we today?" and then, nine times pout of ten.... "We.... are....in.... THE UK!!!!!!"
I can never hear Mr Tumble referencing his spotty bag without automatically assuming he's talking about some kind of painful STD that he's picked up.
Anyone remember the PC plum song? Years ago, some MNer said they sang it their head while watching Balamory "I'm PC Plum and I take it up the bum..." . That took up more space in my head than I care to own up to.
Hahaha - and also the little 'bridge' bits, where he sings something like "PC Pluuuuum - keeping you safe now". I always imagine them as his admissions of his corrupt side and find myself singing "PC Pluuuuum - I mugged your granny"; "PC Pluuuuum - I burnt your house down"; "PC Pluuuuum - I drowned your puppy" 
I was a bit disappointed when I googled Robert the Robot and saw him without all his makeup and robot gear on.
I can't be toooo specific, but when he's not robotting in Justin's House as his sideline, his main job is on ITV daytime, arbitrating in minor financial disputes between friends, neighbours, colleagues etc.