First, thank your lucky stars you didn't end up in III.5. ;) Manon's spot on about the arena - there's no need at all for that many bleachers with so few premium seats. That's a recipe for disaster when you hit a bad stretch and don't have the promotion bonus to bail you out.
You definitely need an exit strategy for your older players. With three players at 32 and another three at 31, and none of your trainees probably ready to be starters, it'll be rough. Hopefully you can get a safe spot and sell the 32 year olds before the deadline and get enough money to buy a few guys in the 30-31 range if you're looking to save up money, or younger and better if you're going to invest more in players for next season.
Longterm, though, if the guys you're training aren't going to be enough to bring you out of III, that means you're going to have to buy a team to move up or train other guys instead. And buying a team to get out of III will be expensive if it's not a one-year II or bust old man farm. But this is where you need to figure out your plan for the future - if you want to move up at some point, you need to figure out how you'll get the players that will help you do it, and the more of those you can train yourself, the less you'll need to buy.