there are what is referred to as tracing rules. so for the interest to be investment interest the proceeds of the loan would have to be traced to being deposited into your investment a/c. doesn't matter what type of investment is purchased.
from the MLP you will get a k-1 that will need to be entered into the 1065 k-1 section of your return. you will not be able to file until you get the k-1 and don't expect it by the end of January. many are not released until close to 3/15 and others are not released until close to 9/15. distributions are not taxable unless they exceed the basis in the partnership. this you will have to track because Turbotax doesn't. when you eventually sell the broker will report your basis as the original purchase price. this will almost certainly be wrong. the partnership will send you a supplemental schedule which you'll need to use to compute your correct basis, any ordinary income from the disposition, and any capital gain or loss. yes, many MLP report ordinary income upon their sale - Because the cash distributions are due to depreciation and other deductions that the MLP takes, those deductions are recaptured upon the sale of the units and are taxed as ordinary income
also, be aware there may be multiple state k-1's or a supplemental schedule for the states. even though you don't reside in those states you may have a filing requirement if the income reported for a state exceeds the filing threshold.
more info at these links
https://www.investopedia.com/articles/personal-finance/062515/mlps-how-they-are-taxed.asp#:~:text=Th...
and
https://www.sec.gov/oiea/investor-alerts-bulletins/ib_mlpintro.html
