Each time when I access Note 5, a notification appears to say that "Unfortunately, Google PinyinIME has stopped. There is no button to re-enable this app. It would be nice if I could uninstall it or re-enable it.
Go to the App Manager, select Google Pinyin IME, and show us a screenshot. http://forums.androidcentral.com/am...ide-how-post-screenshots-android-central.html
Thank you for your suggestion. I have to live with the irritating alert message. That link was not working.That looks like a really old version, since Google's current version is called Google Pinyin Input (not IME), and has Material Design icon. You can try looking for an apk file of the old app, but be cautious, because websites that offer apk files don't usually vet them for malware. Here's one possible site: https://www.torrapk.com/en/apps/13-other/172-Google-Pinyin-IME
That's actually done in Contacts, not in the device Settings. When you open a contact, click Edit in the top right corner, then scroll down to the bottom, click More, scroll down to the bottom, and you have Ringtone, Message Tone, and Vibration Pattern on a per-contact basis right there.
Also, B. Diddy's link above works for me, it sounds like your device really could benefit from a factory reset (and then reinstall apps manually, instead of letting it reinstall something bad).
Something is definitely amiss. I too have the SM-N920V (Verizon) model, and this is what the lower half of my contacts look like when I click Edit:
View attachment 230545
Perhaps you're not editing a phone contact or Google contact?
You can always do a factory reset on a clone, because even if it isn't a genuine Samsung phone, it's still an Android phone, and will function like most Android phones.
Use an app like CPU-Z and see what kind of processor it has. If it's a MediaTek (a company whose chips are often used in budget or knockoff devices), then it's a clone, since the Note5 uses Samsung's Exynos processor.