Doesn't seem as my previous post took so let me try again...
Drill point compensation - Pick the "Hole machining" operation and select the holes. In the (left) lower window click "Job assignment" (the 2nd button from the left - depicted as a cross section through a bore) select the hole to modify and press the "Properties" button above. When the "Hole editing" popup window appears, from the drop-down under "Drill tip compensation" select "Drill tip". The hole depth will then be compensated based on the drill point angle to provide a full diameter hole to the depth in the model.
Spiral Plunge - Pick the"Hole machining " operation, select the "parameter tab" then select "strategy". Under the "Drilling type" dropdown select "By spiral". Or you can do a 2D contouring operation and under Parameters\Stretegy select "Helical machining".
I always prefer to pre-drill holes and pockets as in the long run it saves time, extends the life of costly endmills, and just seems easier on the machine. Drilling is always the least costly and fastest way to remove material.