One more thing to consider. What does your future employer say about tattoos? Some agencies and clients have their own dress codes. Many terps work for school systems or government agencies, or have clients with dress codes.
In the hot South Carolina summer I showed up for one assignment that was an all-day VR job training in a piece-work assembly building. I was wearing capri length pants as part of my ensemble; comfortable but not too casual. Was I embarrassed to find out that they weren't allowed in that work setting. Skirts (all lengths) and slacks were allowed but no ankle-length pants.
I've interpreted for older and low-vision clients who can't tolerate any distraction--glossy lipstick, colored nail polish, jewelry, etc.
Some terp companies don't allow sleeveless clothing ever.
The company that I work for has a dress code described in the employee handbook.
I know some terps remove their visible piercings while on the job.
Much depends on the setting, the employer, and the individual client, so there is no one perfect answer. The "safest" route is to either always wear long sleeves, or at least keep a light-weight long-sleeve cover up close by.