Everyone has the same salary floor. You're right that not everyone is maximizing their salary floor. I have minimal contact with Delmado Reds, Plagues and Wild Star, I'm not sure if they are aware of the minimum salary floor. Boston was unaware of it too previously, he didn't really know much about financial management in this game, but still hung around after all these seasons. I did give him some tips and he is indeed recovering, so maybe it's a matter of time before he improves (although it is great to see that he has already gotten a nice arena.
I can understand CMB not investing much in players - after all they're tanking. That isn't something I'd expect you to understand, but I personally have done the same thing as him before (in fact I would have gone 3-19). It's still a gamble, but if you don't do this, you're not going to get your homegrown player who will be raking in the merchandise money in the future (although he has two future franchise players atm, I guess he is aiming for double HOF).
I'm not sure why BIA isn't upgrading. Yes, he's in training mode, but he isn't tanking. So maybe he just never got round to filling up his team. I've previously told him about the salary floor before. That said looking at his roster, he seems to be trying for an all local team. Maybe he just hasn't found the right players? And might have missed out on players such as Joe Asmara.
I guess we just have to remind them to shop at the end of the season - when player prices are low. Also TV Contract depends on the average salaries of the teams in SBBL during the off-season processing. They pick up cheap players to fill up their salary floor, they also get more TV money, its a win-win situation. I agree with you that we badly need to bring up the quality of SBBL, or else it will be hard to compete in B3.
In this situation we difficult to play B3. Now you used more than 1.3mil not included yet staff and arena extra upgrades cost. And you need to pay extra tax cost every week. Whatever your team is rich how long you can survive?
Not sure if you've ever heard of Venomous Scorpions, but it doesn't sound like you have, or I don't think you'd be asking this xD