If you are thinking about a new purchase with a heloc vs a current 30 year fixed rate, this could be a good alternative.Basically, helocs are billed based on the average daily balance of the account.

I see lots of cabins for sale but I’m concerned if the market is strong.

It's a very local question based on the comps and active/recently sold inventory inside the community.

Your first step should be building a strong team: an investor friendly agent, lender, contractor, and property manager are key.

There are a million sites you can look at to get an idea based on more parameters.

Cover your bases for starts and then get legal advice. 

The answer is NO, based on the language of Section 152(c)(3)(A):...an individual meets the requirements of this paragraph if...

I'm based on the west side of the Twin Cities and am investing on MN's North Shore (Duluth, Two Harbors, Grand Marais) The house were under contract for is a long-term duplex. 

They have had many drawbacks in the past but they are quick to put out new features and do actually make changes based on comments in the forums.

However it is largely based off of relationships and working history.