First the good news-be quick and get a big discount-even tough its not FRI here anymore.

Next 2: except for from B onward to PL (1/day direct Krakow, more connections via Poznan or Warszawa)-plus onward from Krk-you do not need any RES-its only optional. You can just do that str8 after arrival in those cities, thus avoiding all the online troubles and no, these trains are not booked solid weeks ahead.

The connection Pr->back to AMS is not that quick-you may also look into open jaw airtickets-go to AMS-fly back US from PRG. Often cost the same. But as global pass is MIN 4 days-it will not reduce outlay.

For untill around march/apr you can find train times on bahn.com= German railways, these will not change very much for later on. There are also NO really feasible overnighttrains anyway along this routing for now, though you could if really wished, use the NightJet Wien-Linz-AMS and get to some point of its trip from Prg. Will not really save that much time.

Now the tricky point: will it save-maybe/perhaps/canbe. Then you compare with the lower advance prices-which also means: no show-money gone. Will depend a great lot on when and how long advance and also your age-if you get discount on pass. First 2 rides via bahn.com, 3d via pkp-intercity-last-in this case better fly-easyjet or transavia, unless you want to see B->AMS also return-there are also other slower ways-more changes, via other parts of DE..

@mcadv, thank you for the quick response! Your tips gave me the confidence to go a head with a Global Pass purchase. The ‘Black Friday’ sale is good all weekend, so was able to get the discount. Now, on to planning our stops.

Interrail is not of much use for travelling around cities as it is only valid on the mainline rail companies (and in Poland many regional operators do not accept it), not the local transport in cities. You will most likely need a local ticket for metro, tram, bus to get around the cities on the days you are staying in them.

Buying a 15 day interrail if you are only going to use it on longer journeys for 4 days is just going to cost money.

Assuming you have the 15 day continuous pass you can factor in local day trips at no cost - A 1 - 2 hour journey each way would give you plenty of options to see a little more of the countries you visit. The man in seat 61 shows places to visit from most cities. This is an example.

https://www.seat61.com/international-trains/trains-from-Prague.htm

@Yorkie, these were my thoughts about the 15 day pass, which I purchased. I just glanced at the link and also at Český Krumlov. Looks like this will be on one our side trips!! Thank you!

Looking at the Berlin → Krakow route, the Rail Planner doesn’t show the direct PKP Intercity train (EC57). There are some shown as ‘Not is Pass Network’. One available is overnight with a train change and the one leaving in the early AM is with 6 train changes. 

I see EC57 on DB. Is there a way to book on this train with a Eurail pass? Or, do I have to pay separately for this with DB?

The interrail app rail planner is unreliable, it is best to stick to the likes of DB planner. That train is valid with your pass, it requires reservation, this can be done through DB.

OOI the German ICE network often has several routings between cities so you can find trains leaving later than others but arriving earlier.

We found this the hard way when our planned train from Munich to Nuremberg (scheduled to take 1 hour) was indefinitely delayed and we were advised of another train leaving 10 minutes later. Imagine our surprise when it took 2 hours because it had a totally different routing.