We have been actively involved with the entitlement side of multi-family investing. 

Seems odd that they would. 

I am involved in my first large deal with a silent partner. 

I am also very involved in reviewing proposals, selecting subs, design, etc. 

Since my strategy would definitely involve house hacking, I was thinking about house hacking with a mixed-use property.It could be interesting to evaluate as a strategy, but only if I can access financing with a low downpayment.How would that work from a financing standpoint?

Yes, your parents can take out a HELOC on their paid-off home to help fund your BRRRR, but it’s smart to have a contract in place to outline repayment terms and protect everyone involved.

People that tell you it’s dangerous may be hanging with the wrong crowd, or involved with different circles or stuck in some time warp.

I was able to switch to bi-weekly mortgage payments to accelerate my payoff at no extra cost, but the odd week payments don't get applied to my mortgage until the even week payments round off the total sum, so it's like I'm giving my lender a free loan for a few weeks each month.

Quote from @Bryce Markey: Don't get involved in personal matters.

@Basit Siddiqi true. the other side of the coin is with rehab situations sometimes there are issues with the property that prevent lenders from getting involved.