eSIM for backpacking across several countries

The plan will not work in a country outside its coverage list, so you would need to buy something that does cover it. The easiest approach is to sort that out while you still have wi-fi, before you travel there, since buying and installing both require an internet connection.

It depends on the validity periods actually sold for that region and on how settled your plan is. If the route can still change, buying in stages is usually more flexible, because you match the coverage to where you really are in each stretch. Check the validity and terms on the detail page of the plans you are considering before deciding.

A profile generally binds to the first device it is installed on and cannot be moved by you. If it happens, contact the team to see what options exist in your case, since the answer depends on the plan and the circumstances.

Usually not. Many travel packages are designed to work only once you reach a covered destination, so showing no service at home is normal. The one thing not to do is delete the profile because it looks broken — a code generally cannot be installed a second time.

It depends on the plan — some allow it and some do not, so check that term on the plan's own detail page before buying. If you will be sharing, size the allowance above what you estimated for yourself alone.