My wife and I are in our high-twenties currently living in UK. We don't have a mortgage, we're renting our flat. The only debt we have is the standard UK student loans, which is deducted from our salaries automatically as a %. We have no debt beside this.
We're currently researching the concept of FIRE (financial independence, retire early) which involves investing extra savings to retire earlier. At the moment we're contributing 15% of our income to our workplace pensions (with further plans to increase it), but we've still managed to accumulate a non-emergency sum of £10K and €5K which we would like to invest (most likely S&P 500 since it's a long term investment), with all future extra savings to follow.
The catch is we're unsure that we want to settle in the UK and are considering moving to another country in Europe within the next few years (Scandinavia, Netherlands, etc.). This is the same reason why we haven't bought a house. All brokerages seem to be tied to a particular country: you can only buy assets while being a resident of that country. Once you change the country, it becomes a problem of transferring your assets there: paying taxes or selling the stocks and re-buying them in the new country - but this may incur losses if selling too soon/on a low. This is my understanding, at least. What's worse is since we're still trying to find "our place", we might have the same problem in a few years once we decide to move countries again.
What are our effective options here? Ideally there would be a broker which would operate in Europe in general, so it would be easier to transfer assets from country to country. We're looking for options with the least resistance ideally: I'm reluctant to transfer the funds to another country because from my understanding, this would often require a proof of residence in said country + numerous visits several times per year to manage the finances/related bank account. If it would be possible to manage finances overseas then I'd be happy with this option.
Is it viable to keep the assets in their original countries of purchase, rather than transferring them to current country of residence? This means no longer buying more of that asset and simply letting it be after we've moved out of the country. This effectively yields a portfolio of investments in different countries. How hard would it be to manage such a portfolio? Would dividend collection be unnecessary complicated?