i was wondering if once you have a house under a straight option contract, if you did not get it recorded could the seller still sale it to someone else who offers more?
If you have a valid contract with consideration then the seller should be bound to sell you the property under the terms and conditions of that contract. If he does get a better offer he could sell it without your knowing as you have nothing recorded to cloud the title. You could record a memorandum of contract to secure your position if you feel this could be a problem. If it does get sold you have grounds for a lawsuit against the seller if you so desire to proceed with it.
No he cannot, unless you have a messed up contract, if he does than you could probably sue, you have the exclusive right to buy the house, or you could assign that contract for a quick profit.