I'd give 6 months on the market and if the house didn't sell my name would come off the title and my remaining share of the profits is forfeit and the house is owned entirely by the money partner.

If you don’t and walk away, the contract likely also says you will forfeit the earnest money.Always read your contract and/or seek legal counsel to understand your obligations.

I offered to lease the property month to month at a rate 25% higher than a 12 month lease, and have his security deposit forfeited if he left prior to 3 months, and 50% forfeited if he left month 4-6.

Either way the simplest solution that could get the deal done for all parties involved could be to have the seller escrow X months of rent for the supposed cash payers, which would be forfeited upon a case of non-payment for more than X days by any of those tenants.  

He agreed to forfeit his deposit in order to pay this months rent/late fees, and to replace the most recent window.

Also, refer to the money that he pays you as "Non-Refundable Option Consideration" if he takes possession and begin to pay rent, his NROC is converted into deposit monies (and a lease is signed), if not, it is forfeit.

With this new agreement and forfeiting the deposit it doesn't sound like you were left with many, if any, protections or guarantees on how the property is returned. 

If you go to an OZ, you forfeit the potential of continuing to step up the cost basis of the exchanged investment at death ...4.

*  What requirements and contingencies (i.e. umbrella and earthquake insurance policies; ex to forfeit some or all of her share of equity to make me whole, etc.) would you include for protection against possible forms of loss (i.e. lawsuits, natural disasters, mortgage default, property neglect/deterioration, etc.?

If they flake out, that deposit is forfeited.