Re: Training fees
I enjoy teaching enthusiastic students it would be easy for me to forget about money while teaching, but those I rent from don't seem to be so easy going. They never seem to be willing to let a month slide when the funds aren't there.
Then there is also the fact that my time is valuable, the several thousand hours I spent learning the art, the time spent learning to teach it, the experience that comes from teaching something way over two thousand+ hours of classes. Then like's been mentioned the time it takes from business, mortgage company isn't sympathetic nor is the grocery store.
What I would do for a senior student that's been with me a long time is lot different than someone who I don't know that walks in the door and tries to bargain with me right from the start. I sympathize but I have had people try to haggle with me that it turned out later that they could easily afford to pay the normal dues. There is really no way to judge a new student's character. It's not exactly fair to core students who are paying their share in time and money to keep the place open.
An experienced student of the same style new to the dojo that pops in once or twice a month really isn't of much value. It's possible that might be a mat fee if it was never more than 1-2 times a month but it would definitely be a conversation and I'd probably call their previous school to get some understanding of their backstory.
"Teaching for free at a youth center" sounds to me like you have a rather idealized idea of teaching. Even at a youth center, funds have to come from somewhere, charity or otherwise.