. - Costs and Returns : In overly general terms the cost of doing business in Oregon, (especially on complex property types) is more manageable in Oregon in comparison to let's say...California?

You need to factor the cost of refinance (average $7K which may change depending upon the price of your home)

I understand I have to find the right loan and do the math, but is there really any other downside to the FHA and that additional insurance cost? 

It costs $300 a year in MD to maintain an LLC. 

Which one of the paid lead generation sites are you finding most effective for getting lead lists and which mail houses are the most cost effective? 

It is only fair that you pay them something in a situation like this and you need to consider what this is costing them not only in hard costs but in the inconvenience and lost opportunity.

While mortgage rates are a non-issue for you, the challenges of rising insurance costs and market fluctuations might deter other buyers, potentially lowering competition and prices.

Well besides the hard costs (construction, materials) and soft costs (permitting, architecture, fees, engineering) people often forget holding costs. 

Seeking stable, long-term housing can lead to longer tenancies and lower turnover costs, which is what many Section 8 renters are after.There are, however, disadvantages to take into account.

The $$ I will save on the closing costs can offset the slight negative cash flow that I may encounter.