Halfway there

Committed to get BMI to middle of the healthy range, I've just reached the halfway point losing 11 pounds at the rate of a lb every 5 or 6 days over 55 days. I started in the overweight range of almost 27 BMI and now, at 167 lbs, am just about to transfer from the yellow to the green on the BMI chart. My plan is to lose 11 more lbs and get to the middle of the healthy range. What I'm wondering is when does your strategy and yor behavior start to change as you get into better shape and closer to your desired weight?

When do you switch MFP to calculate net calories using 1/2 lb a week instead of the 1 lb/wk as it is set now?
When its time to add 250 to 300 extra calories a day, is it OK to do it with a beer and and a late night snack, or better just to have the whole sandwich at lunch instead of just a half? (I'm afraid I know the answer)

My goal is to transfer smoothly to a maintence routine, one I can keep to for the long haul.