No patient can see a 4cc difference in implant volumes, particularly with different types of implants and the addition of a modified vertical lift--these changes are much more drastic and visible than less than 1 teaspoon volume increase. The lifts would make your breasts higher and tighter, and scars will be permanent, but will fade, settle, and soften (as well as perhaps widening a bit) over 6-12 months. Do not expose your scars to ultraviolet of any kind while they are pink (including tanning beds) or else they may turn permanently brown!
At 4 months post-op, your sternum should not be sore any longer, unless you are extremely active and your pectoralis major muscles (attached to the sternum and ribs) are causing your discomfort. A supportive bra (or two) when exercising or running may help to reduce this. Scars are expected to be pink for many months, but each patient heals at different rates.
See your surgeon if you have concerns or questions! Good luck!