I know conventional lending could become an issue depending on the condition of the property.

There's a good chance the issue(s) you face has already been discussed and answered.Ask questions in the appropriate forum.

The issue is the down payment is over $250k and no one has that or is willing to fork over that amount.

Numerous times I have been able to think through an issues that arose on a construction site and saved the Owner by proposing an alternate route to resolve it. 

The snow companies that are good can be really pricey and we have had issues with some of the smaller guys in past.

Unless you negotiate a new contract or addendum with your PMC, they do NOT have to abide by any requests/demands you make that contradict what's written in the management contract.If they have in fact NOT followed the terms of their contract, then you'll want to send them something in writing pointing out the specific language in their contract that they violated and ask what they plan to do about it.If they fail to correct or address the issues, then you'll want to start looking for a new PMC.

Since the original loan remains in the seller’s name, you may need a nominee interest allocation to deduct mortgage interest, as the Form 1098 will likely be issued to the seller.

If there are any legal issues that I have to worry about etc. 

One thing to consider on the credit card option is that a lot of contractors don’t accept them so that could be an issue.

There are probably a lot of hidden issues wiht the house.