Erm, it's not the noise I'm bothered about.
DD hasn't wanted to go outside today because "that boy keeps looking at me". Normally she's outside come hell or high water.
I've felt like I've been watched all day too.
The trampoline is about 6 inches narrower than the decking. I'm not sure how much they shift but with a 18 (guess) stone man and fairly hefty 6 year old bouncing full pelt I doubt it stays still! If the kid managed to fall off I guess he could hurt himself quite seriously falling from 5ft up.
It would be no problem on the grass next to the decking (although their washing line might need moving to do that). Other side of their garden would be brilliant as there's a big shed between that side and the house next door to that so their privacy would be maintained.
I'll try and have a chat with them in the week.