It sounds as if you are very fond of the hedgehogs, but what you have said rings several alarm bells to me.
Firstly, chuckles and snuffles. The noises you describe don’t sound normal to me. They sound as if they may, possibly, have a lungworm infection or the like – although it isn’t possible to tell, only by descriptions given on the forum. The best thing to do is to find who is your local carer by ringing the BHPS on 01584 890801. You will be able to tell the carer more precisely what they sound like and take advice.
Regarding the hedgehog who died. Except for some specific circumstances, ie. Nursing mothers, who occasionally come out, (but would be likely to be in shade under bushes) it is not normal for hedgehogs to be out during the daytime and especially out in the sun or in the open. If a similar circumstance arises again put the hedgehog out of the sun in a box and offer food and water (and leave the food and water there – most hogs are not likely to eat or drink immediately after being caught even if they are very hungry). Then you need to contact your local carer (as described above) urgently. The hedgehog may have been dehydrated or otherwise ill and past being able to drink for itself. Again, describe all the circumstances to them – and take their advice. It is also not normal for a hoglet to fall asleep on the lawn and is an indication of a problem. If that happens again, follow the advice above.
Regarding feeding. The best things to feed hedgehogs are good quality hedgehog food, cat/dog food and/or cat/kitten biscuits – and nothing else. There has been much written on the Forum about the dangers of mealworms. They are bad for hedgehogs even if they do like them and are implicated in Brittle Bone Disease. It is best not to feed mealworms at all, although you may need to reduce the amount gradually. Hedgehogs natural diet is high in protein. In my opinion it is not a good idea to feed them suet pellets, which are very high in fat. It is not natural for hedgehogs to eat such large amounts of fat and could lead to problems for the hedgehogs similar to those found in humans if they ate large quantities of fat – i.e heart problems, etc.
I am not familiar with cat kibble with soft centres, but imagine that the cat/kitten biscuits are better as they help to keep their teeth clean. So my advice would be cut out everything but cat/dog or good quality hedgehog food. This should lead to healthier hedgehogs.
It is also a good idea to leave plenty of water in your garden every day, 24 hours a day, in case a dehydrated hedgehog (which you may not see) is desperate for a drink any time. Preferably some in the shade. I use large plant saucers for water and have them both ends of the garden. At the same time try to make your garden more hedgehog friendly. Lots of tips on Hedgehog Street.
I hope you will take this advice in the spirit in which it is given – we all want the very best for all hogs. But don’t be too hard on yourself – remember, we can’t know something, until we find out about it. I hope that, in time, you have some healthier hedgehogs around and that they do, indeed, produce some hoglets for you to enjoy watching.