From Ireland, but work and live in Europe & US (IL). Work is Derivatives Trading/IT.
Welcome to the board.
Here are my opinions (from a 28 year old, so take it for what it's worth):
Q1: Convert it all. Sure, people can make arguments about long-term trends of US trade deficits, etc., but the same could be said about potential stagnant growth in Europe with the Euro, which could effect the Euro's strength. I'm the very conservative type, and if I were in your shoes looking at a roughly 1.25:1 exchange rate, AND you were planning on living in the US for the rest of your life, I'd take the money and run. After all, if you're in the US for the long-term, you WILL have to convert it eventually. Why not go ahead and eliminate your currency risk now? If you don't, you will have to add currency risk among the interest rate, market, systemic, and a whole boatload of other risks that you may or may not be able to diversify against. OTOH, if you're planning on living 6 months/year in Ireland the rest of your life, then leaving a good stash in Euros makes sense.
Q2: No idea. Ask a tax lawyer/accountant. Are you mainly asking about if the tax-havens are as good as people say they are? Just be careful about where your official citizenship is - I have no idea how the IRS views income-earners in tax havens if they're still officially US citizens.
Q3: If you're looking at 3.5% rental yields, and really want to get into real estate, I suppose you could. I've done business with FISN.com (a CD broker), and they offer oustanding rates on callable FDIC insured CDs (6%). Sure, the CDs are callable, but even if you get called after 6 months or 1 year, you still get a pretty good rate (they also have multiple other CD yield options, ranging from flat-rates to step-up CDs). Also don't forget
www.penfed.org for the Pentagon Credit Union and your local credit unions for great rates on FSLIC (Federal Savings & Loan Insurance Corp) insured CDs.
Q4: Not sure of your question. Being the conservative type (similar to JG), I'd rather have the (relatively) guaranteed fixed income cash flow, so I stick with that area mostly.
Q5. You mentioned that you are fairly low-maintenance. I'd pick a nice but reasonable (i.e. non-McMansion) house in a nice area at the lower-end of the market. That way, if prices do tumble, a lower-priced house has lower absolute dollars to drop (also, percentage decline might be less than the McMansions, as people leave the McMansions for cheaper homes that they should have bought in the first place).
Q6: That has had several threads in its own. Pluses for Canada are health care (although there are residency and even 'buy-in' requirements that I'm not sure about). Given what you've mentioned so far, I'd be more concerned with what activities you're planning on and the areas you want to be in at this point. Take a few trips in Canada and in various parts of the US to start working up a short list.
Q7: House arbing...well, see my earlier answer about me being 'risk-averse'
...I managed to avoid investing at the top of the internet bubble because I kept telling myself "As soon as I pay 450x future earnings, the market will drop". While there are many pros/cons about housing prices, I'd suggest picking a house you would be happy to live in, in the event of house price stagnation/drops...unless you really like to take risks/gambles.
Q8: Everbank.com is one bank that offers foreign currency-based CDs and other similar instruments that can offer some foreign currency exposure. I don't know of many others. See if any of their offerings are what you're looking for.
Q9: I, personally, will never lose the "control over my own money" thing, and would never give a majority of my assets to other managers (I do have a large minority of my assets in municipal and a few stock/REIT ETFs, but a majority is under my direct management). If you have enough capital and a low enough income requirement, there shouldn't be enough of a problem doing it yourself, especially if you are interested/willing to go mainly fixed-income (once you set up a fixed income plan and execute it, you don't need to check prices on your bonds/cds/mutual funds, etc. every day - just withdraw the money from your MM account and have fun!
). While we're a minority, there are a few of us on the board that prefer a majority fixed-income investment strategy (both those already ER and us youngins).