International travel and swimming (Bern)

Is the water going to be warm enough in Bern to float down the river ...June 7, 8?

Possibly, probably not. You don't see many swimmers unless the temperature gets to the high 20's, or even better 30°C. That is more likely in July and August than in June.

What is comfortable weight to lug all over Switzerland streets, etc

Whatever you are happy carrying. Is this a wheeled bag, or a backpack? I suggest you experiment carrying (or rolling) your bag for 5 minutes.

When you land at Zürich you will go through immigration (passport check). Zürich is a well-organised airport and this should be 5-15 minutes. Then you pick up your bag and carry it through customs, which takes no time as most people aren't stopped. Global Entry is a US thing and only applies in the USA.

First, customs, immigration, and security are three different things. In the US we often use the word "customs" to mean all three, but in Europe they use the terms correctly. Customs is control of goods; immigration (passport control) is control of people; and security can involve both.

Going from DFW to ATL to ZRH: assuming you are one one ticket, when you check in at DFW, your checked bags should be labeled ZRH (make sure). If they are, you will not see them until Zurich. You should also get both boarding passes at this time (DFW to ATL and ATL to ZRH).

You will go through security in DFW (using your passport and your boarding pass to get through the checkpoint), and your passport will be checked by the airline (the airlines get huge fines if you aren't admitted to a country, so they will make sure you have a passport, even though it is not needed to leave the US). You do not go through customs or immigration (so, your passport won't be scanned or stamped here).

In ATL, you most likely do not have to go through security; you definitely do not go through customs or immigration, so just make your way to your departure gate for Zurich.

On landing in Zurich, you will go through immigration (passport control), then pick up any checked luggage, then go through customs. Immigration can be fast or slow, depending on how many agents are on duty and how many other flights have landed, and cannot be predicted. Just make sure you use the correct lines (you do NOT want the ones labeled EU, EEA, CH; you want the ones for All Others). Customs in Europe is just a matter of walking through the Green Channel Nothing To Declare line. Unless you're "randomly stopped for additional screening" (possible but rare), you're done.

On returning to the US, you will check in in Zurich and get both boarding passes. Again, make sure your luggage is tagged DFW. You then go through security and passport control. You only need to deal with customs if you are getting a duty-free refund, exporting something unusual, etc.

In ATL, you will go through immigration; HERE is where you use your Global Entry. You then pick up all checked luggage and go through customs. Right outside the customs door will be a "baggage recheck" area; you leave your checked luggage here (since it's tagged with your next flight from ATL to DFW, it gets routed correctly). Why do they do it this way? Because when flying to the US, the rule is that you go through immigration and customs at your first point of arrival in the US; your other flights are then domestic ones with no other "formalities."

So, after re-depositing your luggage, you put away your passport, and go to your next flight. You will have to go through security since you've left the secure area. Your arrival in DFW will be like any domestic arrival (no customs or immigration).

Notice that in this whole process, the ONLY time Global Entry comes into play is on arrival in Atlanta, when you go through US immigration. Otherwise, it's irrelevant.

By the way, it's all easier to do than it is to read about (or type out!). Just follow the signs and the crowds, and ask immediately if you're unsure, and remember that you won't be allowed to skip any necessary steps.

The Global Entry Card seems to be a source of a lot of confusion. I had a long discussion with the CBP folks at my GE interview to make sure I understood correctly. My understanding is as follows: the GE Card is only used at land and sea border crossings. Its not a substitute for your passport. Your GE status is coded into your passport information which is what you use when you enter the US from another country. The Card is not used for this. You scan your passport on reentry to the US.

I've entered the US three times since getting GE, and at no time was I asked for the GE Card.

You can be asked to show passports at several points in your travel, but that is a security thing, not an immigration/customs thing.

Weight of carryon bag? Yes, the lighter the better. Lots of tips here on packing light under the Travel Tips link, and a zillion threads.

PS here is what it says about the Cards at CBP website:

"Using Your Global Entry Card

We accept Global Entry cards for lawful U.S. entry at land and sea ports of entry.

Global Entry cards have radio frequency identification chips, which enable their use at Secure Electronic Network for Travelers Rapid Inspection (SENTRI) and NEXUS travel lanes when entering the United States at the land borders. You must follow all program rules for SENTRI when using this card at the Southern land border ports of entry.

You may use this card for expedited entry into the United States via the SENTRI and NEXUS lanes. The card is not valid for entry into Canada via the NEXUS lanes.

Only your passport or lawful permanent resident card are accepted at Global Entry kiosks. The Global Entry card cannot be used at Global Entry kiosks. . . . "

Was going to say "short answers" but it turned out longer than expected!

Global Entry is used only for returning from a trip outside the US by air and is only to help speed you through customs and immigration here in the US. There are kiosks in the immigration check areas at most US airports having international flights. They are clearly labeled and usually a dedicated officer to handle the GE people is present.

You will always go through customs and immigration at the first airport you land at in the US when returning from outside the country (unless you are lucky enough to start your trip from one of the airport around the world which have US Customs there, then you simple walk off your arriving plane like it was a domestic flight). This means all of your checked baggage is retrieved at that point, inspected by customs (if they feel the need) and then rechecked to your final US destination. Each airline has a bag check inside the immigration area where you recheck your bags to DFW in this case.

The Global Entry card has zero use when flying. I have used mine as ID for TSA security when I lost my license and was waiting for the replacement.

You get TSA Pre Check along with Global Entry. But it is not automatically applied to your flights. Enter your Know Traveler ID into your profile on your airline's web site and you will get the TSE PRE indicator on your boarding passes for the airlines that accept the number. That would be almost all US based airlines for domestic and international flight as well as many international airlines for flights departing the US. The list changes often, check it out on the TSA web pages. And TSA PRE only works for flight departing from a US airport. It gets you nothing outside the US.

I watch the weight of my carry on very carefully when I am flying any part of my journey on a foreign airline. They seem to care more about this than US based airlines. But I always aim to be as light as possible because if I am luging my bag through the streets of some ancient European town, I really don't want to be worn out by the dead weight. My limit is 20 pounds (or 10 kilos) or whatever weight the airline I am flying restricts me to. And I never use a wheeled bag.

First and foremost, being from Atlanta, I apologize for our Airport.

Before our first family trip, I made everyone pack their luggage with an emphasis on light weight. We then went on a 3 mile hike with several places where they had to carry their suitcases up stairs to simulate a train or metro. After the walk, my wife and daughter lost half their luggage weight.