Weclome to just answer.
I will answer your query one by one-
1) About your donor site from where the graft was taken-
It will take one week minimum for the superficial healing to take place which will minimize the discomfort. To fasten the healing the best would be to leave that area of palate undisturbed,this is done by giving an acrylic stent to the patient, it is an orthodontic plate which patient is asked to wear for minimum 7 days which reduces th chances of dislogement of blood clots and helps in fastening the healing process. You should go back to your periodontist
and ask him to make one for you.
2) Something about your graft and its healing-
Once the grafts are placed superficial healing takes place by 7-10 days. The connective tissue fibers present at the interface between the graft and recipient bed will start organizing from 2nd day and may take several days.The complete healing of a graft of Intermediate thickness is completed by 9-10 weeks
whereas Thicker grafts may require about 16 weeks
.Functional integration (i.e blending /combining of parts to function as one tissue) of the graft occurs by 17th day, but the Graft is Morphologically distinguishable from the surrounding gum tissue for months.This graft than eventually blends with the adjacent tissues and appears pink,firm and healthy as ones own gum tissue.
3) About the bruise on your cheek-
The bruise which is you see on your cheek corresponding to the the area where graft is placed might have happened while operating on you or while handling soft tissue(cheeks) pulling or pushing movements, There is nothing much to worry about it and it will get better in 2-3 days times as healing progresses, avoid touching it and if it hurts than you can apply oragel on your cheek part which will minimize the discomfort.
4) Your 4th query about the kissing post op + infection:
Kissing will not cause any infection to your site or hamper healing,also you are meeting your boy freind after 7 days on surgery
and things are expected to get better by than,avoid forceful tongue movements which might disturb the graft at its site or the site from the palate causing discomfort or slight bleeding.
The best for you will be to get a acrylic stent made by your periodontist which will secure the clot at palate until next coming week.
Maintain excellent oral hygiene whihc is very important for graft healing, use your mouth wash twice daily without dilution and avoid eating hot and solid food until you are absolutely comfortable - you should be fine is another weeks time.
I hope this answers all your questions.Feel free to contact me again if you have doubts and we can discuss it again.
I wish you well!