Is the transaction once removed, meaning I personally want to buy the house (I'm not making money off of the purchase of the house, but the remodeling done).

The transactions should be:Investor -> Wholesaler -> SellerBut my contract I had wasInvestor -> Seller To try and compensate he then sent me a copy of an assignment which I refuse to sign since he needs it signed by the seller.

You need both for wholesale transactions unless you are doing a double close.

Even though you try to spell out responsibilities you will experience some cross over in responsibilities.  

Initially I thought about getting a hard money loan and doing a traditional transaction so that my in laws can get their money right away, however time is not of the essence Someone also told that me to save money (avoId poInts/fees/Interest) and just “partner up” with my InLaws and write a contract stating that upon the sale of their house, they’ll get their 400K and I’ll get the rest, have them give me a quitclaim deed to the property and i’ll pay their mortgage and expenses during the rehab months.

If you have partnered with your Ira &  lend $$ from your IRA in the scenario described it will be a “prohibited transaction” and blow up your Ira. see if you can get a non recourse loan from an allowed person, Ira, or company. 

As a condo owner it made prices stagnate as this limits the buyer pool to conventional and cash transactions.

As private lenders, we prefer this as it gives us more comfort that the purpose of the transaction is business purpose and we are not providing a loan for an individual's primary residence.  

With so many parties involved in a real estate transaction, the waiting is the hardest part.

Be very careful with “wholesalers” in South Florida majority of them send out daisy chain properties they don’t have under contract and just mark up other people’s deals.