You should never remove an IUD yourself. A medical professional will be able to remove an improperly positioned IUD, though if it isn't in a harmful place, often they will leave it as surgery is more invasive than the device. If you're concerned because of pain, go see your doctor. If you're concerned because of the way the strings feel or their length, your doctor can trim them for you as well.
No, they are made to fit.
An IUD does not tickle. It is not something you feel when it is in place.
The IUD does not "float," but generally remains in place at the top of the uterus.
Weight change will not affect the location of an IUD
Yes and it can cause serious problems if you become pregnant while the IUD is in place.
Very very very very unlikely. Purely down to the IUD. With an IUD, protection is something like 99.99999999%.
A woman should keep an IUD in place until she wants to conceive, until the hormonal IUD reaches the end of its useful life, or indefinitely if she is not concerned about the IUD's effectiveness.
Yes. The IUD is effective when it's in the right place, at the top of the uterus. If it comes partially or completely out of the uterus, you can get pregnant.
An IUD is put in by the doctor and made to fit so it wouldn't come out of place unless it was put in wrong, but I doubt that would happen.
It is possible to get pregnant with an IUD in place.
While the hormonal IUD can't be relied on for birth control after its removal date, there is no harm in leaving the IUD in place after its removal date.
The IUD should remain in place and not become dislodged after sex, and there should be no pain while wearing the device.
If you go to full term the IUD will probably come out when the baby is delivered.