I was thinking to be fully committed you would need to throw as much time into this as a person possibly could.  

You will make it work if you are commited to making it work.

Now that I am nearing 70, a 2 year mortgage commitment scares me.  

I already have 2 buyers interested in buying the property for anywhere around 30k to 40k so pretty much just need him to commit to my offer. 

Meanwhile, if you need the extra cash flow for another project, you have not contractually committed to making the higher 15 yr payments every single month. 

We regret that wewere not able to rent to you at this time, for the following checked reason(s):  The rental was committed to another party at the time we received your application.  You indicated disinterest and/or declined our offer of the rental unit.  You tentatively qualified, but the rental was given to another party with equal orbetter rental qualifications, or to another qualified party that applied earlier.  You needed to meet our conditions on rent, deposit, co-signer, use, or other.  You did not provide requested documentation in a timely manner.  Previous landlord/other references failed to provide needed timely information.  We were not able to hold the rental until the date you were able to pay the depositand/or initial rent, assume tenancy, or meet other stipulated conditions.  You did not meet requirements on pets, occupancy, smoking, cars, or other terms.  You did not meet our standards for references, income, felony, credit, history, etc.  Your application was denied based upon a written credit report with optional FICOscore; directions to receive a copy may be obtained by contacting us below.  Your consumer/credit report did not contain sufficient information.  You submitted an incomplete, inaccurate, unclear, or unsigned application.  You did not provide a phone number, call back, or return our calls or emails.  You did not submit the required screening fee.  Other_____________________________________________________________.Submitted Screening Fee:  Since your submitted fee was used in the processing of your application, we regretthat we are not able to return any back to you  Since your submitted fee was not used in the processing of your application, we arereturning/refunding your payment totaling $ _________________.Federal and State guidelines limit us from giving further details other than name, address,and phone number of any consumer reporting agency resulting in denial (by contacting usbelow for a free report copy with right to dispute).

We have other commitments until mid May but we are learning lots from BP and all the tools here.

She said I could make the offer without this money committed, but said most other buyers are offering it, and if mine doesn't the offer may not be seriously considered.

You could have an attorney draw up a promissory note that your father signs (keeps things from getting difficult if other family members are involved), and then put the money into the renovations with a commitment that you receive a portion of the upside for helping....everyone wins!

If your 100% committed to development  it wouldn't hurt.