The 2-3% points in extra cost are worth it if you plan on using as I described above because the use would be for a few  months at most and due to that short term use you can survive a rate adjustment up.But, if you have no plan to payoff the debt like when using for a down payment on a long term hold why pay the extra cost for flexibility and have the additional risk of the adjustable rate with the amortization looming when you can get a fixed rate second mortgage. 

NEVER borrow from a 401K, you are taking pre-taxed dollars and paying it back with after tax dollars, you do not get to return the loan with pre taxed dollars, in addition, some 401K plans do charge interest and maybe even fees, and lastly if you get laid off for some reason, it is a distribution with all the "fun consequences: tax at the last dollar rate, and if you are under 59.5 there is also the additional 10% penalty.Personally I like the HELOC, however you can also sell stocks and do tax harvesting there to offset gains if that is an option

In addition to the interest of the loan, you'd also be paying this as well. 

Adding additional bathrooms (like a master ensuite) can be a game-changer.3.

These are professionals with additional training and a stricter code of ethics.

That is an additional savings. 4.

Am I getting greedy to ask for an additional seller credit at closing to help offset some of repairs needed?

Additionally, many states offer property tax exemptions, significantly reducing expenses.

In addition to refinancing, DSCR loans, and cash-out options, we now provide our services for all property types, not just those from NetWorth.

However, nearing retirement, with our past experience in mind, we decided to try it again, this time just rehabbing one house to flip.So, I set up a self-directed IRA so we could use the retirement money we had left after the recession, and bought a foreclosure house that needed a lot work.