Typically outer layer pours are a bad idea. Outer layers have lots of components and traces that tend to chop up the pour. Little islands of pours lead to EMI issues.
If you do a star topology for your +5V (branch from the supply rather than creating loops) with really thick traces (0.020" min) then you could possibly do away with a couple of pour layers. It will certainly reduce board costs. Depending on your supply usage, you might be better pouring the GND and delivering one of the 15V supplies via traces.
In the end you'll have to build a board to see if it meets EMI, and performance specs.
Simply put, toe and heel are the areas of the solder joint that extend from the front and rear of the lead/pad. Think of a solder pad on your PCB as a piece of paper, and think of your hand as one of the leads coming off an IC package. If you place your hand in the middle of the piece of paper, the "toe" and the "heel" are the distance between the tip of your fingers, and the palm of your hand, to the edges of the paper. That's the extra solder in the joint that extends farther than the actual lead/pad on the IC itself.
Here, they are recommending a specific amount of toe because it will provide mechanical reinforcement for the joint. Since there is no room for a suitable heel, given that this is a castellated package that will sit pretty much flush against the main PCB, the only way to add more solder to the joint is to expand outwards, and thus they recommend to give it some extra toe.
To comply with their recommendations, you'll have to turn off the default stop layer and cream layer for the pads, and draw them by hand. This is as easy as going to the properties for the pads to turn both of those features off, and using the rectangle tool, selected to the tStop and tCream layer, to draw the features.
Based of the picture, it sounds like they recommended a tStop that matches the recommended pad exactly, and a tCream layer that matches the pad exactly except for the edge opposite the package, which would extend out 4 mils further.
Best Answer
If this question is asked on the aesthetic look of the text then there really is no better way than the look you want to achieve. It comes down to your opinion.
There are some additional things to consider when making that aesthetic choice.