I think the form should be filled in straight away - I always do as soon as I can. For example, one of my mindees fell over at toddlers last week and banged her cheek (poor little thing) and my book is at home. I therefore waited until they were having lunch (as that's what I do as soon as I get back) and then completed the form. Otherwise, I do as Katymac does and complete it as soon as the child is ok for me to.
As for tv, it could look like I have my on all day but I don't - I'd have no problem in a parent asking me about it though. I'd just explain that it's on first thing when they arrive for my own ds (gets switched off when they walk in) and I put it on for a short amount of time when I am cooking the evening meal to calm them day ready for dinner and also to stop any problems when I'm in the kitchen (as even though I can watch them through the hatch, they'll quite often play up if they think I'm not there )