Mike Cartier,
The first question would be if they don't have any down payment why would you even consider doing a lease option with them in the first place? You could have pre-screened them, introduced them to a broker and/or financial counseling or done nothing. Outside of those, there really isn't much you can do but give them a chance to perform as MikeOH implies (quite correctly I might add).
Things work differently in different parts of the market. If you are doing a L/O with someone in a 50k house with no down payment and a repo, I agree with MikeOH, there is nothing you could really do to help them qualify for a loan, especially these days as the riskier loans have pretty much gone away. I wouldn't do a L/O in that area of the market either. Those who do get financing probably would be 5-10% if you were lucky. Sure, you can argue that they say they can improve their credit over a year or two and qualify for a loan and you are giving them a chance they would not have had otherwise. True enough and really no argument from me here. Realistically though, most won't be able to get a loan in the best of times because they won't do what they need to do to qualify, i.e. pay their bills. If that is the part of the market you like, so be it and good luck.
Now things are different in say a 200k home and in the upper ends of the market. This buyer obviously makes way more money, understands they are going to need a down payment and have a much better chance of success in getting financed. They have way more disposable income. Maybe they are self-employed but make good money and know they don't have enough saved to get a prime loan today. There are many reasons they won't qualify today. Will they get financed in 1-2 years time? Maybe, maybe not but there chance is much higher than the lower market T/B. Also remember, you are the one deciding who gets in and who does not. Granted, things are a moving target more so these days than in the past but you should know up front what the chances of them getting financed down the road are (within reason). A mortgage broker screens all mine so I have a reasonable idea of what they will qualify for BEFORE they get in the home if they perform, as they should. So if they have no chance to get financed, they don't get in. Period. What is a reasonable conversion ratio? That is up to the individual investor to decide.
Fewer and fewer qualify for loans these days without a doubt. Is it going to be harder to get T/Bs financed over the next few years? Yes. How much harder depends on how well you screen them upfront. You are providing a service to give them a chance to be a homeowner if they do what they know they need to do to get it. Things are certainly a little harder these days but things will improve eventually. When? I can't give a good answer other than a guess but I think things are going to get worse before they get better, which is good for all of our businesses. It is unfortunately time to pay the piper.
Pick your market and know your market. What is ok with me may not be with someone else and vice versa. I won't tell someone how to run his or her business. That is their decision. Our job as an investor is not to be their best friend and financial advisor. If an adult says this is what they want and they can do what they say they can (and have a reasonable chance given their good performance) I am not going to deny them that chance. If they don't do what they say they would and perform as they said they would, then so be it but they had their chance. If they do perform and have trouble, I will do what I can to help them. My motto is firm but fair. The saying "It is not show friends, it is show business" rings true.
Happy Investing. I will try to learn to write a post that is not a mile long one of these days.
Mike C