Actually, I had a very pleasant surprise on reading the "fine instructions" on the FBAR form this year. As far as your employer is concerned, you only need to report the name and address of your employer - it says specifically NOT to include the account number or balance information if you are a US citizen working outside the US and have only signature authority over an employer account. Page 8 of the FBAR form, top right hand side:
Modified Reporting for United States Persons Residing and
Employed Outside of the United States. A United States person who
(1) resides outside of the United States, (2) is an officer or employee of
an employer who is physically located outside of the United States, and
(3) has signature authority over a foreign financial account that is owned
or maintained by the individual's employer should only complete Part I
and Part IV, Items 34-43 of the FBAR. Part IV, Items 34-43 should only
be completed one time with information about the individual's employer.
The question of joint investments with non-US citizens is one of those issues we'll have to watch. I think they're going to find they bit off more than they can chew with the current FATCA reporting stuff, and the precise instructions will change over time as they work things out. (Honestly, the raising of the FATCA threshold to $200,000 for foreign residents and the FBAR thing above were last minute changes.)
If you partner in joint investments, I'd say make sure you have a solid agreement between the partners on precisely how all income (and losses) from the joint investment are to be split. As long as the partners are non-US citizens and have no tax obligation, you just declare and pay taxes on your share, report the existence of the partnership however you have to and move on.
As far as joint accounts or investments with a non-resident-alien spouse, Pub 17 is pretty clear that the income should be reported according to local law - which generally means however your local laws expect you to attribute joint marital property holdings or if you have a pre-nup or some kind of formal agreement. Unless the amounts involved are really large, the main thing is to have a rationale you can document for why you reported what you did how you did.
Cheers,
Bev