Hello brother as far as i know and understand there are 2 things u should NOT do
1.u should not sponser your brother because it makes VO to think that your brother will not come back after studies.
2.you should not apply through a college because visa ratio is very low for people who applied for visa through college in a couple of years.
NOW YOUR QUESTIONS.
1.Yes he needs to show that he can pay his fee and bare his living expenses for 1st year so its 10,000$ for living+tution fee of 1 year + return expenses.And he needs to show a bank account which had the amount required for all the expenses almost 25,000$ (i guess) for 3 or 4 months.
2.showing IELTS to OV is not a visa requirement but if your brother has got decent marks in ielts(more then 6) then he should attach the IELTS with his file too.That makes a good impression on VO(visa officer)
3.visa processing time is 11 weeks on CIC for pakistan.But it can be less then that or more then that.
I hope i have answered you questions.
BUT U SHOULD MAKE SURE BY ASKING THE SENIORS.
GOOD LUCK