OK, cool. Well, I have some good news for you. 5 lbs a week would actually have you down 40 pounds in 2 months. So that is probably a bit lower than needed. Could aim for something like 3 lbs a week and get to eat a little more and still be close to that 40 pound goal in 3 months. Might even make it given you are being extremely active.
Now, as far as 5 times a day, there is really no added benefit to eating this way unless you like to do so and it helps you adhere to your diet. However, with so few calories in your daily plan it would be a lot easier on you to eat say 2 times a day, 3 max.
I like shakes but not for dinner, they just dont fill me up enough at night. Better imo to eat a real meal. Save the shake for during the day when its harder or just less convenient to prepare a meal.
Best thing you can do is make sure you stick to your planned calories as much as possible. To do that I would recommend measuring and weighing out your food for at least a few weeks until you get a good idea of what you are eating. Knowing you have x amount of calories everyday to work with you can pick and choose food accordingly simply by looking at the calories and making sure they fit and fill you up.
Worry about diet first, exercise second. Its just an added bonus but its the diet that is going to get you the results.
If you have any other questions just shoot. I know others will chime in sooner or later.