1) Arena definitely needs work. Have a look at some of the other arenas for ideas, and build up.. definitely do at least 1000 bleachers, 2000 if you can afford it..
2a) I would suggest train train train. You need to work out what you train and from there work out how many guys you need. I dont know your players at all, but i would suggest you want to single position train PG, and train PRESSURE for Outside Defence, and you can also mix it up with passing training. If that is how you want to go, save your money for now and dont get any new guys, as the 3 you have are all good prospects.
Just make sure that each of those 3 players gets 48mins per week at PG. So when setting lineup, set 1 guy to starter/backup/and reserve, and try not to have anyone on the bench that can play that position to avoid subouts. You want each of those 3 guys to get 48mins per week at PG position.
2b) If you are going to train players, you need to get a good trainer. Most people recommend a SUPERIOR trainer with fitness skill as you will get lots of pops from players, without breaking the bank. If you are patient, you should be able to get 1 of these guys for about 400k with salary less than 20k.. cheap salary is important as salary goes up every week..
3) I would hold off buying any experience players at this stage. I think you have a squad definitely capable of winning any relegation battle. They look to have 2 guys going bot, we possibly have 1, so if you finish 6th, you should easily win relegation battle against a bot, but i think u can finish 5th... I would not waste the initial cost or salaries until you know roughly where your gonna finish, and u can buy the right piece for relegation if required. Use the money on arena upgrades, but towards end of season try to keep 2-300k in reserve in case you need to buy an experienced player.
4) scouting i would suggest you are possibly going to finish 5th-6th, so that gives you a good pick, especially with a few bots we may have. I would suggest you spend 20k per week to give yourself the best shot. Do not spend any points until after ASW, so you can do the SCOUTING COMBINE and then sort your strategies from there. If you can spend 40k great, but this season should be about making as much cash as you can, and i think $40k is unnecessary.
So to sum up, i would say priorites :
1) buy a superior trainer if you dont already have 1, around 400k for less than 20k salary
2) invest whatever is left in stadium, starting with bleachers.