I would not take my snake for regular check ups if not unwell.
I only would take my snakes to a vet if I couldn't identify the problem and deal with it myself.
Even then, I am not confident in most vets knowledge of reptiles, and would use them to send off blood or fecal samples for analysis rather that ask them to take a look and make a diagnosys.
But I guess it depends on your experience level.
Regarding mites, not too worried, They are easily treated and there should be no physical contact with them in a vets. But vets are like hospitals with air bourn microbes and such. We are much more likely to get an infection in hospital than at home. So going to hospital for me is a last resort. The benefits have to outweigh the risks.