unless your friends have actually applied for spousal pr and gone through the process, then there is no reason to listen to them. listen to the people here with real life experience with the process.
no, age of the sponsor doesn't matter. if there is a large age-gap, then yes, maybe the officer will take a closer look. this isn't always the case.
as others had said, his salary is not a concern for cic when it comes to spousal sponsorship. since there is no minimum income, it doesn't matter how many kids the sponsor has. as long as you can clearly show you guys can support yourself without welfare (which you seem to have plenty of proof of), stop thinking income is an issue. there are MANY people who successfully sponsor their spouse and have 0 income.