All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is permissible to observe prayer behind the Imam that leans up on something when standing up in prayer, since the essence of the very act (i.e. standing up) is realized. Mostly, the Imam would not lean upon something unless he is unable to stand with no help of such a thing upon which he leans – a case under which he is obliged to stand up while leaning upon something.
Even if the Imam does so (i.e. leaning upon something in prayer while in no need to do so), his prayer is still valid but with dislikeability.
We meanwhile apologize for not answering your second question, as we have clarified in ‘Enter Question’ field that only one question should be sent at a time and that if many questions were asked, only the first question will be answered.
Allah knows best.