As long as you are taking care of it nothing would happen and it should be fine.
When they're healed inside AND out; it'll heal outside first. Don't mess with them too much or with dirty hands because then you risk infection or migration.
An inverted or occluded nipple piercing needs to be done by an experienced professional body piercer who knows how to properly do an inverted nipple piercing. The technique is some what different from a standard nipple piercing, skill and knowledge needs to be used in order to correct the inversion. I have done many of these "repair" piercings with the end result being a proper outward displaying nipple. The inversion is partly due to the beast connective tissue and how the ducts and nipple connective tissue seems to be too short thus causing the nipple to be inverted. So find your self a body piercer who has at least 5 years of better of actual piercing experience or be prepared to travel to have it done correctly. Knowledge of human anatomy is a must to complete this piercing properly, but trust me once it's done right and healed you will be very pleased.
If your jewellery is starting to look too long then your piercing is shallow and starting to migrate and will at some point in time fall out of the piercing.
Absolutely...ice helps to bring the swelling down, but as long as you don't put it on for too long, and the piercing itself isn't constricted too tightly. I have a nose piercing too, and i do it all the time.
Well the piercing needs to heal, this can take up to a year for a piercing to become seasoned (this is when you can remove the jewellery for a few hours and not have an issue putting it back in). Average heal time can vary from piercing to piercing from 4~6 weeks for some and others a lot longer. Light heals are not considered "healed" and can be damaged by removing the jewellery too soon.
Well if it's male nipples and they have enlarged already, it's too late. Once the nipple enlarges, which it always does with male nipples, then there is nothing you can do. it's going to stay that way. It's a normal thing the body does to compensate for the jewellery in the piercing. Once the jewellery is taken out it will shrink a bit but not as it was prepiercing. Now if it's a female nipple and the piercing has enlarged the nipple it too is a done deal and will not return to the "before piercing look" once it's pierced and healed it's like that to stay. However with the jewellery removed from the piercing and left out perminently the nipple will receed a little over time (6~8 months) but it will still be noticably larger than the unpierced nipple. This is why most body piercers do not want to pierce just one nipple because people eventually want the nipples the way they were before the piercing. If both nipples are pierced and healed then when the jewellery is removed the nipples will receed a bit and at least look similar without the piercing holes being noticable. Sensitivity with the nipples will also return but only after an extended period of time, they will never be hyper sensitive like the prepiercing sensation but they will become sensitive as they are with jewellery in the piercing.
Male or Female it doesn't really matter too much. I like to stay centered as much a possible this allows the nipple to *enhance evenly without developing a droop, all nipples *enhance once they have been pierced ( * they get slightly bigger in diameter ). Some piercers think if you go just below center you can avoid damaging milk ducts in the case of female nipple piercings, this however doesn't matter, the body will clear a path for the ducts regardless of the piercing should lactation be needed.
the hole will close over or it could get infected
You can go to an oral surgeon and have the web clipped, or simply get a tongue web piercing.
If your jewellery is starting to look too long for the piercing the piercing is migrating and will open up at some point and drop the jewellery out.
I think that Colorado standards are good. Any piercing except nipple and genital can be performed on anyone over the age of 13. I am not saying that at thirteen you know you're going to want that hole for the rest of your life, just that you're starting to identify yourself and piercing is one way of doing that.
The barbell is too long for the piercing and should have been shortened after two weeks, get a shorter barbell in the piercing and it should settle down.