With the exponentially growing national debt and inevitable taxation to follow I have started seriously looking into international commercial and multi family for the first time.  

@Arshad HussainWe do not have the full information, but I suspect that your CPA was correct but did not explain it well to you.You were probably trying to eat the cake and have it, too - which is not possible in taxation. 

The cost might outweigh the benefits.It's really up to  you to decide whether you want to:do it yourself and hope it's good enoughbecome knowledgeable in real estate taxation thru classes or bookshire an accountant to do it for youhire an accountant to review what you have done yourselfOnce you start growing your real estate portfolio, then a good CPA can become indispensable with proactive tax planning. 

LLCs (you don't know if they've elected taxation as a corp or as a partnership, so they all get one.3.  

When an IRA engages in a trade or business on a regular or repeated basis (which frequent flipping becomes) then the IRA is subject to taxation called UBTI meant to level the playing field for tax-paying business and protect them from unfair competition.So, generally an IRA is better suited to truly passive investments like holding rentals, private lending (such as to unrelated flippers), and syndications.

Luckily US tax will be considered when you pay Canadian taxes to avoid double taxation, yet there are some cases when that's an issue to be carefully researched.

- Maybe most importantly, does your CPA specialize in real estate taxation? 

In order to adhere to the law, I would need to refile my (domestic) California LLC as a foreign LLC operating in Colorado - resulting in double taxation, right? 

In order to adhere to the law, I would need to refile my (domestic) California LLC as a foreign LLC operating in Colorado - resulting in double taxation, right?

During that time, I built many pro forma spreadsheets and the only line item in them that dealt with taxation was "property taxes".