Help me Analyze my first deal (Potentially) in New Jersey

I found a FSBO in South Jersey who owns a 3/1 SFH rancher free and clear. All utilities are electric (no gas, no central air). Property has a one car driveway and has W/D included. The home is in a C area. Property is in good condition and rent ready.

She's asking $75K. The reason she is selling is because it was her fathers house and she doesnt live there anymore. She used to rent out the property but had to evict the last tenant and on top of that she is disabled, making it difficult to maintain the property. 

I believe I'm in a perfect position to acquire the property using seller financing, which i have a few questions regarding. Before I go into what I think I should offer, lets get into the details:

Comps/ARV w/ central air: $115K rowhome. DOM: 9 days

 $146k rancher w/ +200 more SF. DOM: 21 days

Rents w/ no AC: $1300/month (no driveway) tenant pays all utilities. DOM: 28 days 

 $1450/month (2 car driveway, rancher) tenant pays all Utilities. DOM: 48

Expenses (Annual) 

 Taxes: $2,643=^ $3,000 

Insurance: $1,200 (estimated)

**42% Gross Rent: $6,552 =^ $6,750

Total Annual Expenses: $10,950

**(Property Management 13%, CapEx 9%, Vacancy Rate 8%, Repairs 7%, Misc 5%)

Monthly Expenses: 10950/12= $912.5=^ $915

In order to determine what the maximum monthly amount I can offer the seller I subtract 1300-915= 385. I want to cashflow at least $175 per month, thus 385-175= $210. I can offer her $210 per month, conservatively speaking. I am meeting with her this Friday and I believe I can offer her a low down payment (no more than $4k) and finance the rest with her. 

Question 1)- If we agree to the terms on Friday, what paperwork will I need in order to solidify the deal? 

Question 2)- While i was writing this, it appears that this FSBO is listed with an agent on the MLS. How will this potentially jeopardize my deal??

3 options I'm willing to offer her:

1) Full asking @ $75k w/ $2k down. $73k @ 30 years =  $202.7 =^ $205/month (call the round up good faith interest) at the end of 30 years the value of the loan will be $76,800. 

2) Offer $65k w/ $3k down. $62k @ 25 years = $206.6 =^ $210/month At end of 30 years the loan payoff would be $66k

3) Offer $65k w/ $4k down. $61K @ 30 years = $169.4 =^ $175/month. At end of 30 years the loan payoff would be $67K

Once I meet with her Friday i'll get a better understanding of what her financial needs are and hopefully we'll be able to help each other out.

My exit strategy:

1) Buy and Hold indefinitely while cashflowing at least $175 per month, using the reserve funds to ultimately rennovated/modernize the property and install central air, increasing the appreciation.

2)Lease Option w/ non refundable down payment. I believe this property would be a perfect candidate for a rent to own situation. I would screen potential buyers asking for a non refundable down payment of no less than $5k. The property would be marketed as "Rent to Own, $1,000 per month" for 10 years which equates to a property value of $120K. By finding rent to own buyers, not only would I receive immediate cash in the form of a non refundable down payment, my monthly cashflow would increase because the new "owner" would be responsible for the taxes and property upkeep. 

Question)- If I am seller financing with the original owner and I am now the "owner" while paying the note, can I still bring in rent to own buyers and set up a lease option even though i'm still paying off what i owe her?