I have a team that has league average salary and 4x league average income
You did have the highest average arena revenue for the season and I presume pretty decent merchandising from Creytz' tenure plus Fisk's been there a decent amount of time too. On the other hand, you're also suffering slightly in competitive terms by only having a 9 man roster and especially thin on big men. If you're training, you're not going to be training GS (which should never be necessary anyway) so you're going to either suffer late in games or have a GS deficit from overplaying the starters.
Which isn't to say you're doing bad at all. You made the playoffs in a killer league, are improving your roster as you go and have more money coming in than going out. I'm always a fan of trying to train and just making sure you stay out of relegation trouble, and then doing as well as you can within your financial situation. You're doing that, and you could probably afford to add a backup big man or two and still be in good shape, but have a slightly better chance at postseason success. Or, hell, take whatever magic pill I found that pushed me into the finals after being stone cold frigid to end the season.