Yeah that does seem really low for even maintenance levels, and really low if you are going to be laboring in the heat all day.
Meal #1 up the oats to 1 cup and add a few more eggs.
#2 up the shake to 2 scoops for more pro and cals, and add some kind of carb (maybe a slice of multi grain bread)
#3 unless your cutting, throw in some carbs (brown rice 1/2 cup)
#4 again unless your cutting throw in some carbs (maybe make the tuna a sandwich with one slice of multi bread?)
#5 Really carb up before your workout even if you are cutting (add another cup of oats or a sweet potatoe or rice)
#6 make it two scoops of whey
#7 i would go with another chicken breast to cut out the fat from the eggs, and maybe a 1/2 cup cottage cheese.

I think even by adding those carbs and cals you will still loose a significant amount of weight. Those first totals just seem really low and you dont want to go into a catabolic effect and burn muscle away when your working. Just my 2 cents.