Welcome to Top Eleven.
It's important to win games for various reasons. Besides the obvious reason of winning the competition, reasons that I can think of are:
A) Keeping morale high
B) Earning packs from matches; 1 blue pack for winning and 2 for dominating a match (5 goals difference)
C) Earning the Man of the Match award gives that player a decent amount of skill progress. As far as I know Man of the Match is always given to the winning team when there is a team that wins.
Keeping condition low serves no real purpose. You generate condition at fixed intervals, so the only thing you can gain by doing this is a set number of extra trainings (assuming you would normally go into a match with 90% condition, but you push it down to 0, you'd gain 10 'match practice' total. It's not worth it over the entire season. On top you apparently risk injuring players when pushing training at low condition numbers.
It doesn't matter at all. You can use as much of an asymmetric or lopsided formation as you want as long as you adhere to the rules regarding illegal formations. All you need to do is follow the rules stated here Illegal formation - Top Eleven Fan Made Wiki to prevent playing with only 20% possession (though it's debatable if possession makes any difference)
You could do so, but 3-4 scouts don't mean you will dominate all games, nor does it mean you won't. It's just possible and it should increase your chances to win. There are people who spend a lot more than that and people who spend nothing at all. Either's performance depends on the manager. I've seen plenty of managers who bought a lot of good players but failed to grasp any tactics and thus ended up losing.
Buying top players will increase your chances, but it won't guarantee winning.