When I started training, my teacher only offered class one day a week. His reasoning was simple; with multiple classes, people find reasons to justify (aka excuses) not going to every class. But with only one class -- they don't. Me? I was always afraid that the class I missed would be the one that I really, really needed! I trained daily... even if only for a few minutes.
You have the option to attend several classes a week -- but are willing to settle for the ones that are "required." Realistically -- work schedules and being an adult may keep you from attending every class, but you claim that martial arts are something you're serious about. You want to become an instructor one day. You need to attend every class you can; you need to learn as much as you can. You need to see how different people teach, how different situations that come up in class are handled, and just plain get as much supervised training (practice aimed at improving) you can.
Belts are cheap; less than $10, including shipping, I believe. Buy a second belt. Keep a spare uniform in each car. (I used to always have my training bag with me; it let me jump into a class or training opportunity unexpectedly on several occasions. Now -- I settle for keeping some gym gear around, that I can throw on and train in.)
