Hi Petzneo
Through looking at different threads and other Pharmacy applicant's comments, there isn't much of a difference between King's and LSOP in terms of teaching. Each university will have a different structure to it's course and will be doing different topics at different times, therefore it will be your choice in chosing which university is the best for you. You may also want to consider the working environment, course structure (as some university will put more emphasis on lab work etc) and many other aspects such as chances to study or work experience abroad, like LSOP which allows a limited number of students to go abroad during the end of the third year to partnering universities for further studies. This is explained on LSOP's website.
In regard to how leinent LSOP are towards candidates not being able to meet their requirements, you will probably need to contact them direct or gain some information from current students at LSOP that also use this forum.
As I have received an offer from LSOP, they did not specify a grade A in Chemistry, just ABB in any order. Unless you are aiming for a bursary, which will require you to get an A in Chemistry and another A in a second A-level subject you're taking.
Hope this helps.