You can sometimes format them and write very small programs on them, but it will not last long. HD disks need a higher magnetical field strength than DD disks, but the 1541 cannot bring up enough magnetical field....
It may work better or less good with some 1541-II drives since these had about 4 or even more different drive mechanics built into.
But I would never ever use them if you want to keep what you are copying on them
There were 2 different sound chips made for C64 & C128.
Old ( breadbox ) C64s, flat 128s and 128-D in plastic case have the old SID, while newer, flat C64s and 128-D in metall case have the new SID.
The new SID does sound a bit different than the old one, and it cannot play samples at a high volume ( sometimes you won't hear anything with sampled sound )
So if your C128D is a metll box one and you are used to old SID sound then you might think it is broken, but it isn't !
However, if the sound is completely different and distorted then there might be something wrong with your C128....