This is not a partnership, so no problems. Regarding tax consideration, it is true that you can't use the foreign tax credit, but what does that matter. You should be looking for appreciation and a stock with a good return, usually goes up.
I have a roth ira and a reg stock acct. I usually test out the dividends on foreign investments on my reg acct before I buy em in my roth ira acct. vale has a 15% foreign tax on dividends so no, I will not be putting it in my roth ira acct
The problem with putting high-dividend foreign stocks in an IRA is that you can't recover the "foreign tax paid" (i.e. to Brazil) as a tax credit. So you get the dividend minus the foreign tax paid, and eventually when you start withdrawing funds from the IRA you'll pay regular income taxes on whatever amount you withdraw including accumulated dividends. As long as the dividend tax in taxable accounts is only 15% (on any stock listed on a US exchange), it might be better to hold high-dividend foreign stocks in a taxable account. But if the dividend tax goes up sharply, all bets are off.