protective clauses in purchase agreement (PA)

[Account Closed]

I had an offer accepted via email for a 185k duplex that I told him subject to me being able to attain suitable financing. He wants a written purchase agreement. This is my first offer I've made on a house without an agent (my cousin). I'll use him through teh process but gosh darnit I want to be more independent. I'm studying BIll Vaughn's system in particular protective clauses in forms but you learn the most by taking steps. I used to be a public accountant so I can do the math if I have the discipline and I liked law and contracts but this is new so I want to be on safe ground. 

So I guess I can do the numbers and generate a purchase agreement subject to 

-1 attaining suitable financing

-2 subject to inspection at buyer's expense

-3 subject to current tenants being verified 

The numbers seem good- too good. But I want to get financing with lower money down so I have less skin in the game, maybe 5% so that would mean more PMI so I have to look into that. PMI seems pretty low per the calculator. It all seems really good. Man this seems too easy. What's the catch?

I feel like we're just in the casual stage but he wants a written PA so I have to have everything I'd need. I have to start thinking of the getting him to agree to closing costs or all that stuff, at least so we can begin process of negotiation. What's everyone's thoughts. 

I'm just looking over the Bill Vaughn form. It looks pretty good. I don't know how quick I can get financing in my employment situation. I have lots of equity and some rental income but no w-2 income rn. I can maybe get a guarantee from my dad so that's the best bet or get re-hired in my new career as coder finishing a bootcamp. It is crazy doing deals. This is being on the edge. Honestly the numers aren't so terrible. What's the worst thing that could happen? Why do I overworry? Why am I so over deliberative on everything?