I have a Speed 7 as well and had similar thoughts. The more "serious" solution was to restore and old 1985 road bike. My needs keep changing so I go back and forth.
I have an 11 year old Corgi. I take a trailer along so she rides when she gets tired. We were out for a 10 mile ride today. Both the trailer and D7 break down and fit comfortably in the trunk. The road bike can fit in the trunk if both tires are off but the trailer does not fit then.
The gear inches for the D7 are 33-92 versus 38-108 for the road bike. The road bike is faster but the D7 can pull that trailer and climb better.
I had to adjust the derailleur a few times when the D7 was new. The chain would fall off the smallest cog and wedge between that cog and the frame. I suspect this was caused by the new derailleur cable stretching a bit. The first time it happened, the chain was wedged so tight that I had to use a pocket knife with a can opener blade that fit between the chain links to pull the chain out. It was the only tool available.
I do not notice the kind of noise you mention as clattering now but I cannot remember if it might have done that when new.