I’m definitely not one of the Nissan gurus but when I had a worn down pilot bearing it only made some clutch chatter. You really want to make sure you bled the system correctly and that the release fork is getting enough travel. get someone to pump the clutch, and watch the release fork... see if it moves further depending on how much you pump the clutch. You could also check pedal height...I once had the engaging point set too low and it made me grind trying to get into gears.

Does it still grind if you double clutch it? It could be bad synchros. If that’s the case I would probably pick one off from the classifieds link. I see Ka trannys go all the time for like a hundred bucks.