Initial ideas for opening two minutes

Firstly, we are hoping to go to a location in London, most likely St Thomas abandoned hospital. We would be doing an action/crime film, which would include some western European smugglers and a group of possibly hired assassins or ex military of some sort. We would have quite a few fight scenes and a villain as well as a few chase scenes which will hopefully be intense.
 we hope to have a narration at the beginning to introduce the audience to the plot. Accompanying this is a chase scene, match and action as well as a wide range of music. During the fight scenes, we hope not to have to add music, but have punching sound effects. however, if there was to be any music, it would have to cover the majority of the audio. I got these ideas from some fight scenes in various Batman films, where there is no music, but only diegetic sounds such as punching and talking.
With fight scenes, there will be quite a few slow motion shots, which will be used to capture some movements which are too fast to film. Slow motion shots also enable the audience to feel encapsulated and would increase the intensity. As I and a few of the actors are black belts in various martial arts, our strong point would hopefully be the fight scenes, but the difficulty would be finding the right angles.  Also, a quick blur of the music when it goes into slow motion. However, because the area we are filming in is quite small, we wont be able to do many tracking shots, so we will have to limit our shots to the basics, close, medium, long, over the shoulder, and some others such as still shots. I don't think that P.O.V views would be best for the fight scenes, mainly because it would be too risky and difficult, but it is a possibility.
With chase scenes, there are many locations we could film, but would have to use certain angles to limit the view so that no member of public is in the shot or walks into the shot. There are some good ideas, as many of the actors and I do a sport called Parkour/Free-running, so we are hoping to do a roof jump and have some large jumps, and repeat it a couple of times for different shots. We are aware of the safety precautions but have done the jump many times, so there is a very low risk of injury.
The story itself will be quite complex, but we have quite a similar story to a usual drug bust, for example, a few protagonists, a gang and a villain, but the story is yet to be developed.