aside from initial period of checking and fiddling etc
mine also no adjustment in about 8000km despite checking..
it gets an occasional clean with kero and brush then lube [silkolene]..
she lives on the street, in sight of pacific ocean, gets fresh sea air
up our street with no chain rust..
re; 'seized link' question - before junking the chain, make sure you give it
a good clean [at least soak it with wd40] and lube, let that 'sink in'
then give the link youve identified a good working over..
work them up and down by hand as if something stuck in there
and your trying to work it out.. if it/they resist strong working try
tapping [downward] on suspect link/s as they come away from
the rear sprocket, with a rubber or wooden mallet or suchlike..
its only a chain, exposed to the elements etc, and things can
get in between links and plates.. who knows..
also, keep a good eye on the sprocket teeth for wear,
which is obvious to the eye compared to chain wear..
worn sprocket teeth mean chain wear or imminent death..
plenty of pics/images here and inet for worn sprockets..