Avatars can be earned from hunts or occasionally from the crates that are opened like this weekend. The avatar you pick during the tutorial is also free.
Try restarting the application, that should fix the issue. If it doesn't feel free to email support (support@athinkingape.com) and report the issue. If you email, make sure to include the game name and your username in the email.
Perfect, support will take it from there. They can help address the issue as it's likely a glitch that the game developers can now fix because they know about it.
Misc bonus is a stat boost to your base stats (the numbers in the blue and red bars at the top of the screen). The bonus is applied when fighting/dancing/eavesdropping/pranking (or the party equivalents). If you want to know how much of a bonus it gives to your overall stats, divide the misc bonus displayed on your profile by 50. I hope this helps! Contact me if you have anymore questions.