Gardyloo

The walk would probably take 30 - 45 minutes, downhill going, uphill returning. From the Westin the walk to the Westlake light rail station is around 3 minutes, and the walk from the Stadium station to the nearest ballpark gate is around 5 minutes.

I'm just going to comment on the hotel's location and how to get there from the train station and from the hotel to the Pier 91 cruise terminal. The hotel is over a mile walking from the Northgate light rail station, along either very busy arterial streets then under the I-5 freeway and slightly uphill past a gas station to the hotel's parking lot, OR over the freeway on a skybridge then around a mile on a slightly less busy, but not particularly pleasant street up to the intersection opposite the hotel. Travel time on the train from the International District light rail station to the Northgate station is roughly half an hour, added to which should be the 15 minutes or so from the King Street Amtrak station to International District light rail station, then another 30 minutes schlep dragging bags along the street to the hotel. I don't want to say the walk at the Northgate end is unsafe; I have no reason to believe it would be, but would I do it dragging luggage behind me? No, I would not. I would book an Uber or a taxi or a towncar from King Street straight to the hotel (around 15 minutes, depending on traffic) and call it good. You might end up saving thirty bucks by taking the train and walking, but what's your time worth, or your peace of mind? Just asking. As for getting to the cruise pier from the hotel, same story, except worse. A mile to the Northgate station, say 20 minutes to get to downtown, then a $20+ cab ride to the terminal; probably totaling over an hour and maybe saving you $30 compared to a cab straight to the terminal. Same questions as above. In my view, without a car the whole Northgate area is pretty unpleasant. It wasn't designed for pedestrians, and the relative demise of the Northgate shopping mall (like many of its kind across the country) has left things "in transition," shall we say? If you're locked into the Nexus through your booking, so be it, but if you can change hotels without penalty, personally, I'd do it.

I looked on Expedia and found plenty of cars available for one-way drives; however most involved picking up the car in suburban Seattle and/or dropping the car in suburban Vancouver, and all were very expensive - $250+ per day counting the one-way surcharge. By comparison, flights from Seattle to Vancouver are $104, so less for two than the car for one day. Ordinarily I'd say drive, but for that price I'd just fly and enjoy my days in Vancouver.

Just FYI, an "Alaskan tuxedo" comprises a clean pair of jeans, a Pendleton wool shirt, bolo tie with a gold nugget-covered cinch, and cowboy boots.

During the cruise season hotels in Seattle are very expensive; more so now it seems, due to the resurgence of demand following the pandemic. King Street Station is located south of the downtown core in the Pioneer Square area. The Embassy Suites hotel (mentioned above) is by far the most convenient hotel to the station - it's literally across the street. https://goo.gl/maps/1xLedfQ2bG7hCiH69 Sailing on HAL, you'll be departing from the Pier 91 (Smith Cove) terminal, which is around four miles north of the station. A cab to the terminal will cost around $20. https://goo.gl/maps/9HmsD3ZwyiHzNwwg8

The central waterfront (Pier 66, aquarium, various tourist attractions etc.) is at the bottom of a bluff - maybe 50 or 60 feet, from the edge of the Pike Place market and other "downtown" areas. This bluff tapers to nothing as one goes south, so that by the time you're at, say, the ferry terminal, you're on the same level as Pioneer Square and other parts of the south end of downtown. There are some stairs and a couple of elevators that will take pedestrians from the central waterfront up to the top of the bluff. The one that's next to the Marriott is apparently inoperable for the time being, but the one in the Pike Place Market garage is functioning. Or else one can take the Pike Place "hillclimb" steps from Alaskan Way up to the main market arcade.

The bags MIGHT be forwarded provided the ultimate destination is on the tags. If the OP doesn't tell the agent at TLV about the second flight, or if the first airline's policies are not to interline bags on different PNRs, then the OP could get stuck. I had a long, long debate at TLV with Iberia on a TLV-xMAD-JNB itinerary; the IB agents at TLV (contracted, not Iberia employees) refused to tag the bags to Joburg, which would have meant going landside and re-checking them at Madrid. Sometimes the agents are not as expert as we'd like.

If it's a separate ticket from Rome to the US, your luggage will be turning on the carousel in Rome indefinitely. Why on earth would you take that chance?

Here's a video review of SFO-MEL on Qantas' 787. Looks okay to me.