The answer to this question will depend on the specifics of your lease purchase contract and who bears the "risk of loss" with respect to the house, If, under the terms of the contract, you have had all of the risks, rights, and responsibilites of ownership, you can probably sustain an argument that you have owned the house. If that is not the case, then you will not be treated as owning the property.
Yes, those are the kinds of things that would help. Other things to look for are - who is required to pay the property taxes and maintain insurance on the property? If the taxes (or insurance) go up, who pays the increase? Are you paying the exact amount of the taxes and insurance, or do you pay an approximate amount? For example, if the taxes started out at $1,147.50 per year and go up to $1,319.76, did your payment for taxes go from $1,150 to $1,325 or did it go from $1,147.50 to $1,319.76?