Too early to say this....
In argentinian top level, 2 league rounds played, 4 injuries (a bit high number, considering nobody plays hard tacking), but 2 injuries were really minor (2 and 3 days).
Team physio doesn't save you from injuries, it only reduces them to half at most, so unless your player is supposed to be injured for 1 day, his injury will happen, no matter how good your physio is.
About the tackling stuff.... Easy tackling helps, but only a little bit. I always had the feelling that injuries in this game are similar than quality from academy, some seasons are good, other seasons are bad. If you are in a bad seasons, you will have MANY injuries, no matter how much you care your players (in a season, i had 16, most of them long, despite i played easy tackling in all matches). In the other hand, if you are in a good season, you might play hard tackling in most matches and yoy will probaboy have 4 or 5 medium injuries. That's the feelling i have about injuries now.
About the card stuff, i think it's somehow related with the injury stuff and another random element that i think that exist in matches: how rough they are. I have seen many matches that teams playing easy tackling receives more cards than others using normal/hard tackling, it usually happens when a team is in a bad season (in injury terms) and try to care his players. I always had the feelling that those teams who played easy tackling and got many cards would probably have more injuries if their tackling set would be harder, it's all related i believe.