Anything in an optionagreement could be in a sale contract and vice versa.The legal nature of the two are not the same, one is unilateral the other bilateral, but if there are no penalties for compliance, there is no effective or enforecable difference.There are risks of death, divorce, bankruptcy, loss of income, future claims to the property, liens, judgments, loss from disasters and insured perils, failure to maintain the collateral, failure to pay taxes, title issues and others with any seller finance transaction, for that matter, any financed transaction.

@Chad Clanton  An Addendum is a bi-lateral agreed alteration of the original contract to which it refers

canceling a bilateral contract unilaterally seems like a perfect solution!

Depending on what you are putting into the agreement it might be a bilateral agreement rather than an option agreement.

A P&S agreement is a bilateral agreement.

If you could get a contract in place with the original seller, then you could attempt to wholesale the deal to a new buyer without the need for a real estate agent since you would have obtained equitable interest by virtue of the fully executed bi-lateral contract.However, if the wholesaler will not allow you to go into contract directly with the original seller (or the wholesaler demands his/her fee to assign his contract to you prior to closing to which you would have to come out of pocket a significant amount of cash with no guarantee the deal would close which is typically not a good idea), you would need a real estate license to avoid the appearance of brokering the deal (practicing real estate agent without a license).

They would be ok with it but you would still have a late fee.A bigger thing you should be worried about is that when you have a lease agreement it is a Bi-Lateral contract, they have to perform (Pay rent on time) and if they do not perform you have to perform (Charge late fees).

If you still want to go ahead  consult with a specialized attorney and check the bilateral tax agreements with your countryyou may find 50% ltv loans with high rates which will hinder you returns and defeat the purpose of real estate investing which should be about taking advantage of leverage, mortgage interest deductions, depreciation, etc. that you would probably get in your countryAlso be aware that if you die while holding property in the US. the irs will levy a 50% estate tax on your assets.There is a way to avoid that but it involves creating complex structures with trusts etc..If you want cash flow los angeles is probably the worst place with sf and manhattan to look for.

I will take some time to listen to a couple more and then reach out to you bilaterally. 

:)People, your financing agreement is a bilateral contract, you can NOT assign a financing obligation without the lender/seller's specific consent.