As for gaining the trust of people on scene, if you don't trust me you can always wait for the next rig...
Wow.. now there's a testimonial for how to put the patient's needs first.
On a scene, it's not about you. It's not about your right to express yourself as you see fit, it's not about your desire to decorate your body with ink, metal or T-shirts with sassy EMS sayings.
Competence is not just measured by your skill set. Competence is also showing enough maturity and professionalism to know when your particular choices regarding your appearances are less important. Different employers in different capacities are going to hire people based on their own particular set of standards. Some of these will limit the length of your hair, the presence or absence of facial hair, make-up, hairstyle, dress, physical appearance.. .and all sorts of other ACLU offending personal choices.
Those of us who are grownups know that while we have the absolute unalienable right to dress however we like, when we are asking someone else to give us money to perform a job, we decide which is more important, the job, or the appearance issue.
I have nothing personal against ink or metal adornments. They do not offend me in any way. I do not have any, but more because I'm too frugal than too uptight. There are nurses in our local ER who have varying degrees of body art. However, when it comes to the patient, most of our patients are elderly, many are in varying stages of dementia or other mental impairment. I believe that adjusting my appearance so I don't scare the patients is a non issue. The back of an ambulance, during a major life threatening health event is not the time to teach the patient about expanding their tolerance levels.
Those who get all offended and defensive over something so silly and easily dealt with tells me volumes about their maturity level and their ability to put others first. As an employer, I would have less of an issue with someone with all kinds of body art, piercings etc who says... "Sure, I can cover them up" than I would with someone with a small tat or piercing who is all defensive about it. The issue is not the art, but the attitude.
Appearance is part of competence.