If they put ridiculous demands on you, like no inspection periods, no quality photos, unreasonable closing times then simply move on, it was probably not a good deal anyway.So above are some of the "ugly" cons that are rampant, but avoidable.

It's really all about what terms you come up with and as you get more into seller finance you'll realize there are a lot of finer points and intricacies with structuring financing with the seller.Typically, just like any other type of sale, the seller is unreasonable.

I do not think it is unreasonable for the tenant to rent a commercial auto shop or a bay in a shop for his work if he is at a business level. 

My first assumption would be that the people who have their listing expire are grossly overpriced and-or the seller is acting in an unreasonable manner.   

@Jonathan WilsonDon't forget money for updating/repairs/make ready prior to renting, closing costs and an upfront reserve. 5% for vacancy does look a little low at first glance but, if you feel your tenants will stay 24+ months (not unreasonable for a good single family home); then it is accurate.

This was a simple ACH transfer, not a wire.Deciding this was unreasonable, I opt to use their "Bill Pay" mechanism to "pay myself" since I of course, am transferring the money so as to pay a bill.

It doesn't seem unreasonable to me that someone doesn't have 3x monthly rent and needs a month in order to save for it with a $60k salary.

To get started, I’ve listened to a bunch of BP podcast episodes to figure out the rough outline of how to do this, have built a relationship with a loan officer, real estate attorney, and property manager, found a mentor who has been doing real estate for close to a decade now, and equipped with this team I am going to do 100 cold outreaches per day to RE agents and fsbo sellers directly using Zillow, Redfin, Trulia, etc. to find them for long enough that it would be unreasonable for me NOT to get a deal.

I wouldn't try to go against anything the L/O heavy hitters have given you in this thread, however I would ask just a bit of clarification on exactly what the potential sellers are asking for.If they indeed just want to cancel the agreement on whim then no they can't and if they want that kind of power they aren't equipped to rent their property under any circumstances.Now it sounds as if you are just assigning the lease option (as opposed to staying in a "sandwich" type deal) so if what they want is to be able to review the qualifications of the proposed tenant buyer as opposed to just letting you put any warm body in there (Not that I think you are doing that, but they have no way to know if that is what you would do) that is not unreasonable and in fact is good business on your part IMO.Again the question as to what they want was not totally evident to me.

I believe most Judges would be willing to go along with an occupancy limit of 5 for a small house with only 1 bathroom is not unreasonable.