I was the same way with my poker bankroll when i was playing poker.

As others have said, unless you have deals in the pipeline right now, you're going to potentially burn through the first 3-6 months without seeing any deal close.I would take the package, then immediately turn around and find another job that at least covers your expenses but isn't too demanding on time. 9-10 months of salary as a lump sum is a great bankroll for your future investments, while you still have some w2 income to help qualify for loans .

Say I have a 100k rehab contract, and I want to sell 25% of it to a lender, that way I don't have to cash out anything, and just get paid to bankroll from that 25%.

Just a simple I buy, you sell 50-50 split doesn't do enough.One more thing, if you are asking someone else to bankroll the operation, that someone else should get the majority of the profit or at the very least, get all of his or her capital outlay reimbursed first (made whole), and then you allocate the splits.When I am approached and suggest this structure, the other side often says no thanks. 

Is it generally considered a bad idea to use retirement funds in order to bank roll your first investment?

I am bankrolling all of this information into my mental vault.

I need a larger bank roll to flip more houses at a time.  

That way you can hold onto a maximum amount of your cash for your next venture while having the lender bankroll your rehab.

While I build the bankroll to get the investing started, I've decided to spend a year or two getting educated on the process.  

Keeping it simple, we have flipped 4 successful and very profitable flips to build that bank roll, and are now building our Buy and Hold portfolio while we wait for this Market turn.