We have lots foreign players in every European league, so that´s not a problem in my opinion (actually I like this fact).
You also don´t have too many games per season as Rol stated. Doesn´t matter (two English teams were in the CL final).
By far the biggest threat for England´s football imo are the investors. The league is sold bit by bit which made it the richest and most glamorous league in the world but also the most fragile one. It´s all about the glitter and the current or next Ronaldo. The English football is not down to earth anymore and it´s forgetting its roots and its fans.
And the national team? Sorry, but same procedure every year since 1966. No sign of change or real development. Good players but not enough will to win and many wrong decisions (I remember the world cup 2006 very well - why the hell didn´t they just focus on their goal and bring their girlfriends/wifes instead to buy out all boutiques in that funny little town called Baden-Baden? Ah, the Spice girl and her bunch invading the world cup - a good laugh then. When I saw the first pics of the girls coming out of boutiques surrounded by dozens of paparazzi I knew the English team would screw it again).
