@David Pike
There’s a lot to unpack here, I think your first question is are you a dealer or an investor?
The burden of proof is on you and there is some very specific criteria to meet if you hope to classify it as an investment. See the article below for some info
https://rsmus.com/what-we-do/services/tax/the-dilemma-of-dealer-or-investor-classification-for-real-estate.html
-If you feel meet the investor designation the next trigger is how long you hold the property, if it’s less than a year you will be subject to short term capital gains, if more than one year it will be long term Capital gains.
-not sure it even has to be rented to be considered an investment, who says you can’t hold the property and wait for it to appreciate.
-As far as a cost segregation ( to do them right and have to proper engineering done is very expensive depending on your potential tax burden it might pay off?)
-be aware that when you sell the property your going to be subject to depreciation recapture (pay taxes on the depreciation you accelerated), that can be mitigated by doing a 1031 into another property.
All of this is doable just needs to done right, you should talk to a CPA with experience in real estate to ensure you don’t miss any steps