I love that you rented two of your bedrooms as mid term and short term rentals and made enough to pay for the mortgage and now you are going to use the rental income to show you can qualify for another property.This is an excellent strategy and one more people should consider doing in this inflationary environment to offset the biggest cost in their budget--housing.As you rightly point out, you can use this strategy with every house you buy accumulating a portfolio of houses that you originally started out living in as a primary residence every two years.Well done and more people should consider doing the same, or rent their garage, or shed, or a boat, or an extra car.Love it!

In this scenario, $30k (I no longer do rehabs at this low of a budget) add $60k value of which I get $45k in the 75% LTV cash out refi.  

As you are pointing out - the expenses will all hit at some point if you own for long enough.If you buy a house that needs a new roof and a new furnace within a year... then you need to budget for those expenses in a year. 

We loaned $900,000 on the for the refi and 100% of the rehab budget.

If your parents want a 4 bed two bath and you want a 3 bed 2 bath plus one or two rentals make sure you budget correctly. 

So in my mind STR is good tool to catch long term appreciation and REDUCE EXPENSE when folk is vacationing.For me it is as the following:if you like snowboarding you would buy in Tahoe or Denver or Aspen.if you like beach you buy in Hawaii, Destin, Panama Beach FL or San Diego.if you like hiking/forest you go to these Servier county,etc.The problem is if you don't have hobby and don't like to go for vacation LOLI cut 90% of my vacation budget by having STR, this is the internal profitability metrics LOLIf my own purpose is to make money I would find investment that yield 30% IRR and >1.5EM and I know it's not that in vacation market in 2023 lol.

Unexpected issues can pop up, potentially leading to budget overruns.

(see photos)There is a floor drain on the other side of the 2x6 wall(about 10 feet). so i would just need to tie it into this I am budgeting 20K for a brand new plumbing system for the whole house already since there is not anything in the house currently.The basement floor is already ripped out and down to dirt.

@Victor Saumarez there is no such thing as a budget surplus with an HOA.

My budget is $550,000 and I would prefer the HOA to be less than $400.