Yes, you will need a passport at each end of the journey.
Since Ireland and Portugal are both members of the European Union, they no longer require passports for travellers between those two countries. If, however, you happen to be a visitor from the US who is presently in Ireland but planning to visit Portugal, then you still need a passport, and you should not try to travel on an expired passport. Visit the American embassy and renew your passport.
No you need a passport.
Citizens of the European Union (both the UK and Portugal are members) can travel inside the Union for unlimited period of time without a visa and validity of less than 6 months is not an issue.
If you are a citizen of a country outside the European Union you will need a passport to visit Portugal and may also need a visa. If you are a citizen of the European Union and live in one of the member countries which are part of continental Europe you will still need a passport or national identity card but this is unlikely to be asked for by the authorities on entry to Portugal if you are travelling by foot, road or rail as internal EU borders except into the United Kingdom are only lightly policed if at all. If you travel by air then airlines will ask for a passport or other identity document before allowing you to board a flight even when travelling within the EU.
None needed for travel within US
Yes you need a passport whenever you leave the United Kingdom because you need it to get back again.
If you are talking about Shrewsbury in England, then as both are in England you will not need a passport to travel there.
Yes.
No
Yes
You will not require a passport to travel from Sunderland, England to Falkirk, Scotland.
yes dumbo
Yes.
Yes, you need a passport to travel from England to anywhere outside the EU. You may need a passport, or other acceptable ID for countries in the EU.
only if you are going to Northern Ireland, you need a passport to travel between England and Ireland.
I have danish authority convention refugee passport and want to travel to England. Do I need visa to UK?
You only need a valid passport.