I plan to cut out simple carbs (white bread, fruit, etc) and eat only whole grains
Nothing wrong with that. Might want to read up on the Paleo Diet if this is your plan.
No carbs at all after about 3:00.
No real reason to do this, but whatever floats your boat.
Eat 4-5 times a day
There is little science that proves more meals is better. Standard 3 meals a day would work fine. You might do 3 meals and 2 snacks, which would get your "4-5" times a day and also allow you to fit it into your standard schedule better.
Try to get in a gallon of water a day.
Any reason for this? That is a lot of water and just seems like an arbitrary number you decided to meet for no reason. Drinking plenty of water is good, but you will meet a lot of your water needs through food. Just drink when you are thirsty and try to cut out the crap (booze, soft drinks, fruit juices, etc).