Some interesting points are set by Steve. Let me try to answer one by one:
1. Scouting.
Scouting of national teams is not as easy as scouting for championship. This is because there are many great players in national teams that make it very hard to scout. Their scouting needs to be done not only by scouting the NTs but with scouting through their teams and attributes. But where will you focus your attention on? There are various ways to tackle this questions.
Firstly, and my favourite, is by tracking down their strengths and trying to eliminate them. After identifying these strengths the best way would be by observing how other managers tried to stop them and what was the effect. This begins a back and forth series where you try to identify linkages between performances. Of course in the beginning this will be difficult to achieve but as time goes by with experience gained it will be easier.
Second way is by identifying their weakness and trying to enhance it. By observing the team plays and identifying the linkages between performances, weaknesses will be identified.
For both ways of scouting you should get to really know your players, their strengths and weaknesses. This will help you to know where to search for weaknesses to exploit or eliminate of strengths. You should always have in mind that the other managers also have some ways of scouting and would be waiting for your moves.
2. Draftees
If the manager is not willing to train a prospect for various reasons and the player is considered to become a future NT player i will take the following steps:
a) Try to convince the manager to train the player
b) If the manager is not changing his training schedule for this player, is he is training guards but the player is c, see if he can fit him in his training schedule for a season. In this way the player will pop up, less than by getting trained as a c. Then either convince the manager next season to change training schedule or sell this player. This player will probably sell to someone willing to train bigs, otherwise why buy him, and train him as a big guy. This way we may come to create a very good SF, something that is extremely rare.
3. Called up players.
Roster spots are valuable. Of course no one can determine the amount of players called as this will be determined by the judgement at the time of the decision whether a player is valuable or not in comparison to other players and also in comparison to managers willingness and knoweldge to train. Positions should always be open so that if some talent appears out of nowhere, ie bot teams, to be able to put it on the market and not get lost.
I hope I have answered your queries.