Suggestions on itinerary to Lisbon and Porto

It's great that you're spending a couple of nights in Sintra - it deserves it. Your trip looks well-paced. As concerns language, you're ahead of the game in being able to understand Portuguese, and if you could learn to speak at least the basics of the language, it will be greatly, greatly appreciated.

You can likely see all of those things in Sintra with two nights there. I didn't see all of those things on a day trip, but I really loved the Quinta da Regaleira. Buy tickets to Pena Palace ahead of time (online) to avoid the long ticket lines at the entrance to buy tickets - or go to the Moorish Castle first (and there, skip the first ticket seller if there's any line there and just walk 5 minutes closer to the next one) and buy your Pena tickets there if you can.

Sintra is a nice, chill town, so spending a few nights there isn't a bad idea.

Coimbra could be seen as a day stop off the train between Porto and Lisbon (would need to leave bags in Coimbra and there's no official storage at the stations but you could find a way) - but you are planning to go from Porto so Sintra, so that might make for a long day. Otherwise, it's an easy day trip by train from Porto. The highlight is probably the old university on top of the hill - you can tour it (for a fee).

Belem is much closer to Lisbon than Obidos (which I didn't visit). It's easy to get to Belem from Lisbon by public transportation, but I found the trams and buses mobbed with tourists - some trams were so full that I could not get on and had to wait for the next one, making it frustrating at times to get around. Clearly Lisbon hasn't quite kept up with the surge of new tourists.

I don't speak any language but English. I rarely had any trouble communicating with anyone, though I didn't exactly have long conversations. I had dinner with a couple from Spain while I was in Porto, and they spoke to Portuguese waiters etc. in English.

You might also want to check out the RS Portugal Tour itinerary just to see where that tour goes. We took it three years ago and certainly enjoyed all of the sights we saw.

Belem is part of Lisbon and should not be missed.

"I am Hispanic and would love to speak to them in Spanish (I understand Portuguese pretty well but don't speak it) but I don't want to incur any ire in them either. Please advise."

I was there in 2002, and remember at least two instances where Spaniards spoke to the locals in Spanish, while the locals responded in Portuguese. However, part of that may have been that relatively few Spaniards speak English. I didn't sense hostility per se, but it did feel like a bit of a stand-off. I also remember how few Spaniards there were, compared to the far more prevalent French, German, British, and American visitors.

At the Porto airport, an Italian was using Italian with the check-in agent who was using Portuguese. After a few minutes, the check-in agent suggested they switch to English, saying "it's easier." Since it was not the first language of either one of them, they still struggled a bit (I was just behind them in line, and I think I helped them at least once).

And on this subject: I found a surprising amount of French in Portugal (far more than Spanish, and almost equal to English). I met a fair number of people who spoke Portuguese and French but not English. It's the only place I've used a "third language" (meaning it was neither my primary language nor theirs) extensively. It was so pervasive, that I took to asking right off the bat, fala inglês? francês? rather than just fala inglês? French speakers were quite happy to use it with me - no hostility whatsoever (of course, my French is far from fluent, so while it was far better than nothing, it wasn't perfect for me).

So, I can't definitively answer your question, but those are some data points for you. Again, this is from 2002, so things can change.

One thing to consider: since you have a few months before your trip, you have some time to learn a fair amount of basic Portuguese, and as a fluent Spanish speaker, you'll progress more quickly than I did. Just make sure, of course, to get CD's for Lusitanian (continental) rather than Brazilian Portuguese. Pimsleur, among others, has these; check your library.

Some people think that Portugal is a province of Spain, like Andaluzia or Galicia. As Portugal had a hard time fighting for independence, and has the oldest borders in Europe, if someone who is not Hispanic speaks with someone who is portuguese in spanish, that can be offensive.

From 2002 till now tourism has increased very, very much in Portugal. Lots a people from Spain are visiting Portugal, and also some tourists from Argentina and México, for instance. And the languase used is spanish (not exactly spanish but "portunhol" that is a mix of both languages that are very similar but with a different accent).

People with 50 or more, propably learned french at school as a second language and english as a 3rd, people under that age learned probably english as 2nd and french as 3rd, and nowadays spanish and german are also teached.

Tv in Portugal transmits all programs in the original language with subtiles in Portuguese (except cartoons for children). That helps a lot with english - it is something people hear everyday. Music is mainly in english too, so are computer games, etc.

If you decide to learn some portuguese, choose the original language, as said before. In Portugal brasilian is well understood but tourists from Brasil sometimes have a hard time understanding the natives from Portugal.

About your itinerary - it looks great!