As for doctors, most will have a grasp on sterile procedure, but are clueless in the important areas of jewelry selection and placement. The body parts that give you the most pleasure are the ones that hurt most when pierced, they are also the parts that feel best when healed. Tis better to stretch slowly than pierce at too large a gauge. A piercing for show may be of a minimum gauge. 14 gauge below the neck.
Thin jewelry can feel like wire moving in a piercing and lead to excessive scar tissue build up.
Not a good thing. Also be aware that a piercing started initially with too large a gauge can cause interference with those nerve endings you seek to enhance. In my experience, condoms do not interfere with genital piercings. Quality body jewelry has no sharp edges and should pose no problems. You may want to try a looser fitting condom for multiple or large gauge piercings.