sounds normal….they are not quality items…..
even my Japanese made Hitachi drill spark a little when viewed thru the cooling slots….and is a tad noisy on shut down…..remember there's a lot of weight to slow down quickly….personally I prefer drill to slow down and stop the old way, in it's own time….I find the weight of the bigger voltage machines quite wearing after a days use….torque reaction…
the clunk is all the gears and other rotating bits n bobs coming to a halt….cheaper equipment means lower tolerances i.e. bigger gaps….
providing it's not noisy when working I'd not bother to much BUT u could take it back to where u bought it from and compare with another machine of the same type…
I bought a couple of cheap and nasties from lidil to get me outta a hole when on a job….
surprisingly they worked and lasted well…but with similar prob u describe…..
with this kinda gear u really get what ya pay for…..buy cheap buy twice I'm afraid…..