Product Promotion and Clear Cache

1) If a user is login on Session 1 and created a order and meanwhile loging to another session and did some modification in the promotion and did clear cache, then will happen on the order created in session 1 , will that oders has the updated promotion information? 2) If clear cache button is clicked in a session then it is refreshing cache form that object manager session only or for all the object manager session cache will get refreshed.
3) Recommendations are not coming  for all the promotion in regular manner. For example in a order if a product A is selected then recommendation was appearing for it and when Product B is selected then it is not showing recommendation. If user is login to another session and follow the same steps done in session one the recommendation was appearing for both product A and Product B.