Hello Aspirant!!!

Yes, you can study organic chemistry without having deep knowledge of physical chemistry. Organic chemistry is all about reactions and mechanisms. As the mole concept is the basis of physical chemistry, basic organic chemistry (BOC) is the basis of organic chemistry. If you have mastered BOC then organic chemistry isn't difficult but if you haven't made a grip then organic chemistry is way to difficult. I will suggest that there are some easy topics in physical chemistry which you should do to score more. Hope you are clear. Work hard and all the best!!

Thank you!!!

It depends on your interest level

Ideally speaking both are inter linked but learning is never ending process

According to examinations point of view you can always refer individually