Lips are pierced with barbells all the time, generally bent barbells for vertical labret piercings.
So..........what?
Do you mean that you have an outie? If that's what you mean, then yes. It's not advised though I'm not 100% sure why. You would have to wear straight barbells or rings. Navel jewelry wouldn't sit right. Everyone is different so idk if it'd work but you should look into inverse navel piercings.
They don't do them at all
The only time navel piercings really hurt is when you have the needle going through you. After that unless you bump it on things or it gets infected, it shouldn't hurt.
Straight barbells come in a variety of lengths and gauges, so yes. When you get pierced, your piercer should measure and fit your tongue with the appropriate barbell :)
navel, nipple, genital, and surface piercings that are on the back, abdomen, hips, thighs, etc
no, its not like its gonna go into your blood or something.
Labret posts are best because the backs are flat and don't rub on your teeth as much. There are "lippy loops" that are curved barbells where both ends are on the outside of your mouth.
The eye brow ring is the appropriate size and gauge for the eye brow it's going into, navel rings and sized for the navel they are going into. You should see a professional body piercer and quit messing around before you hurt yourself.
Not long at all, piercings don't heal in a month especially the navel piercing, it takes from 3 to 6 months for a good light heal, but is far from healed and seasoned to handle having the jewellery out for long.
The most popular piercing for females is either lobe piercings or, in recent times, navel piercings.