But I’m mostly concern with how the taxation part works when using a loan company.

I am aware of electing to be treated as an S corp for taxation purposes, but now my question is, can my LLC legally flip houses if my business was created on the basis of investing through rentals/leases?

I have been told that I may need to have a Canadian corporation own the LLC in order to avoid double taxation. 

I am pretty sure I will get hit with taxation at ordinary income rates for FLIP 1, because this is a simple interest structure, but am not sure about FLIP 2.

One of the downsides is that trusts hit the highest tax brackets rather quickly so if this property is producing profits, could be subject to tax at higher rates faster than if you created an LLC. 

If so, there may be exposure to UDFI taxation for an IRA. 

Most likely an LLC in IN.If flipping, I'd elect s-corp taxation to minimize the active and self-employment taxes. 

You carryforward that loss next few year when you have an income to pay less tax or no tax at all. 

how you ensure my proposed structure is accurate, flexible and relevant, so that aren’t any things that will come down the road and increase my taxation, or possibly hurt overall ability to further engage in business planning?

The use of debt-financing in an IRA does create a small tax liability via UDFI taxation.