conducting

As salaamu aleikum,i have two questions if they could possibly be answered.1)does a wali for nikah need to be beside the girl at the time of nikah,or can he be listening over a device where he would be able to hear everything if he is not able to be beside the girl? 2) can the  normal contract of nikah (2 witnesses,wali,agreements of man and woman,and mahr) be come valid if its made via the internet? i.e using microphone ,typing it out,etc. since there is not a possible way currently for the parties to meet.?

Is it allowed in Islam for the nikah to be conducted while both the groom and bride are present together in the same room, seated together in presence of everybody? I don't understand segregation if you are getting married like some people insist it should be.