If you are deemed a dealer, all your properties will be considered inventory and taxed at ordinary income rates when sold. 

If the same tenant occupied for four years, I would probably chalk up the paint to ordinary wear-and-tear because I would freshen it up before putting it on the market anyway.The cabinets are beyond ordinary wear-and-tear for a four-year period.

I have a lender who wants to lend me 100k to use in our flipping business but was wondering if there was any way to structure the deal so the interest that he receives is not taxed as ordinary income.

You're reducing tax on profit from ordinary income to capital gain at the least and in the case of many of my investors - tax free.5.

If the proceeds from the sale will pay off the mtg, it just an ordinary sale.

Example: a tenant used a pile of leftover bricks behind a shed, that were of no value, to construct a very nice sand-based patio in a spot of the yard near the house that has always struggled to have anything grow there.

It has a nice little front yard and a nice patio area for the back house.

., it is not your career), the federal government places a limitation on how much of your passive loss from an investment on something such as real estate can be deducted against your ordinary income.

If funds are kept in the 457B plan, they can be withdrawn before age 59 1/2 without any penalty and only subject to ordinary income tax.Depending on your tax bracket, it might make sense to withdraw additional funds to invest in real estate instead of doing so in a SDIRA.  

It certainly isn’t out of the ordinary and unless they gave you reason specifically to not use them then I would move forward.