Glad to be here to help.
Re. temperature issues.....not uncommon in thin women who live in cold climates, just not talked about much.
1) Silicone implants are not toxic to blood vessels in the chest so throw that idea away. I hope no practicing plastic surgeon told you that......especially if they were board certified.
2) Being thin and looking for anything near to what you have presently you might be best served with a "Hybrid" flap/implant procedure. This usually allows the implant size to be greatly reduced and at the same time provides the overlying warmth and softness of natural tissue......consider this. BodyLift is a significant undertaking and usually reserved for those with no other quality option.
You may not need implant change out over time.....they don't expire and only are exchanged for problems/size issues/desire for different filler material.
3) Yes starting first of year should give you good chance of being done in a same year time frame.
4) As we've moved forward with the GAP procedures we have learned that taking less from he donor site is ideal. So we try to carefully design the incisions to minimize the impact.....ironically, women who are more thin in the glut tend to have less of a contour impact. Those with thicker fat tend to produce more of a potential for transitional differences between the surrounding thicker tissue and the donor spot. Efforts at moving the incisions very high or away from the best blood flow have produced the risk of fat necrosis in the flaps so we do the best we can to marry all that together to get the best tissue quality/best blood supply/and minimize the donor site impact.
Happy to help, call Liz for a list of patients that may be similar to you.