Dependent visa requirements

Hi all,

I'm on Tier-1 and I've to apply for dependent visa for my wife in 2 months time from Karachi-Pakistan. I've got few queries

1) Do i need to change her last name as mine, does it help in visa in any mean?

2) I'm a contractor so i earn combinaiton of small monthly salary and quarterly dividends, will it be ok for British HC to provide last 12 months minimum salary slips and dividens vouchers? or should i explain or add something else too?

3) I'm living with my mates but the house is currently on my name and so are the utility bills but in electoral register i've got 4-5 names added under my house. Will it be fine if i apply for my wide visa with this accomodation or there's a risk of overcrowded objection?

Last but not least if someone can point the list of documents British HC requires at Karachi?

Many Thanks
Faraz