I am thinking about taking out 5 to 10% to fund a down payment on my next live in multifamily house hack.

What would standard down the payment be? 

This would raise our mortgage by ~ $700/month, which is a lot, but still makes our total mortgage payment well below rental on a 4bd, 2 bath.So, my question for the great minds of BP is, is this a good idea?

The mortgage payment is $1,000 on each house, so you earn $500 per house or $2,000 monthly.

I'm looking to invest between $50k and $75k as the down payment. 

Some special assessments are already board-approved for 2025 and 2026 to help raise capital for such items, however I know when the time comes there will be a loan which likely demands a higher monthly payment for owners -- reducing my cashflow. - Based on sale of other units in the complex, I believe my current equity to be roughly $160,000, a little more than 50% equity. - The condo is currently leased through April 30, 2025. - August 2025 will be 3 years since I moved out.

You can allocate those proceeds any way you want - as equal down payments or buy one for cash and others with loans - It doesn't matter a bit as long as you use all of the cash and purchase at least as much as you sell. 

I have two questions regarding mortgage interest tax deductions.First, last year, I purchased a HUD property at a significant discount and used a $70,000 HELOC from my primary residence for the down payment.

Which do you think a tenant will pay first - their car or rent payment?

I offered them 10% down, interest rates favorable to me, amortized for 30 years, but with a balloon payment after 3-5 years.