please please please Urgent help required

Hi all
I have recently got my ILR on 10 years basis and my wife will be switching to partner visa from PSW.There are few things which I am clear about in regards to the requirements for her visa application and looking for an urgent advice.
1) Accommodation - You have adequate accommodation for family, the property must be occupied only by the partner,yourself and dependants applying with you. what does this mean, can we not share flat with our flatmates or friends, what if someone is living with friends.
2) there is a question which goes on saying, where do you plan to live together with your partner? what address are we supposed to give as we are not sure where we will be living in future as we are currently renting a flat and sharing with friends.
3) proof of your age and your partner's age...we have not got birth certificate handy, what can we do in this situation.
your advice will be highly appreciated.
Regards
Laxman