I'm using Fedora 24 KDE, I'm facing two problems, they are:

1. Wifi password not saved after changing the user password
2. I'm getting endless lock screens.

First problem: Sometime back I changed the password of my user account, since this change whenever I turn on or wake up, I'm being asked to enter my WiFi password, I don't remember if Kwallet was enabled at the time of the original installation, but remember disabling it, I don't like other things to remember my password, maybe this was after I typed in the WiFi password, I can't remember. Is there a way to make it remember WiFi password without enabling Kwallet, or can it be limited to just WiFi password?

Second problem: This problem started happening from yesterday morning, after the screen is locked, when I want to get into desktop, I type my user account password at the lock screen, after that the screen becomes blank as if it's going into desktop, but a fraction of a second later the same lock screen appears asking me to type the user account password again, this continues on like this no matter how times I type successfully type the password, it's like I'm getting endless lockscreens.

I have to CTRL-ALT-F2 and use "loginctl unlock-sessions" and CTRL-ATL-F1 to get back into desktop. Is there a way to permanently resolve this problem?

I can't really speak as a developer, but as a long time KDE user, I can tell you that the kwallet system is an integral part of the KDE experience. You can always configure your credentials on a per-app basis and not let kwallet save everything.

For example, I have an encrypted kwallet setup protected by my gpg key, and use it to save my passwords for WIfi, VPN connections, Kontact passwords and the occasional connected LUKS encrypted hard-disk.

Of course, every time I try to perform these tasks, I could also choose not to save my passwords. But I tend to slide towards using password managers to remember my passwords (which are randomly generated strings of gibberish, so I can't even remember them if I want to), while my password managers are locked by a strong passphrase. So if security is your concern, you should look into a complete LUKS encrypted setup, and password managers.

Your lockscreen issue seems like a bug you should file.