if you write it in one hush, maybe you could make it one post then i could see all your suggestions when replying ;)
1. like it!
2. i believe this will overload the page, i think it is enough when it is avaible at the bottom of the player page.
3. many teams have player who switch positions that often, that i don't think that this will work or give decent results.
4. Same doubt like 3, two game are a very small basis and that teams forfeit their away match for example is not uncommon, which will lead to "weird" results. But when they find a way, to do it it would be nice.