Do I first get the approval of my mortgage broker, which means I would have to reassess my condo, and then pay a fee? Consequently, will my property taxes go up? My property has doubled in value, but my income has decressed so far that I have not been able to refinance. I need advice.

It sounds like you want to refinance.

I don't think you need a property reassessment for refinancing, but that really depends on the local and state real estate laws. But, if you must, all other things equal, your property taxes will rise since you claim your condo is worth more now than it was when originally assessed.

And finally, there's no law saying you have to put your brother on the title if that's what you're getting at. You don't have to tell your lender that the money that came from your brother is a loan, you can tell them it is a gift. If you were just asking whether you should out put him on the title out of courtesy, I'd have to say no. The less people who own it own the property on paper, the less confusing it's going to be come closing time when you sell it.

How do I make sure that he is reimbursed if something should happen to me?

If you mean what I think you mean, you could take out a life insurance policy and list him as the beneficiary. If you were implying something else, then I have no idea.

I would like to set up this "arrangement" so that the money he has loaned me, is an investment in my property. When the condo is eventually sold, he would receive his % of the profit. How can we make his investment a legal aggrement?

It appears that what you are looking for is a second mortgage to your brother. It would be junior to that of the bank or whatever that holds the first mortgage. That way, if you were to die, your estate would sell the condo, first pay off the bank, and then your brother, and what is left would be paid to your heirs.

Alternatively, you could, in most states, give him a joint interest in the condo. Or you could leave the property to him in your will. You should consult an attorney in any event, because these solutions need to be done correctly, and some of them may require consent of the bank.