Let me help a bit :)

First a general guide : https://www.seat61.com/interrail-and-eurail-reservations.htm

What did you buy exactly for the first Eurostar to Amsterdam? If you bought something on eurostar.com it's a regular ticket and not a passholder reservation. You may well save the pass day for another day in that case.

Amsterdam - Berlin : seat reservations are optional so you're always allowed to board. However it's a popular route so I'd recommend booking seats for peace of mind -> 3€ through ÖBB or 4.90€ through DB with seat selection.

Berlin - Krakow : there is a convenient direct EC between both cities, departure at 10:52. Reservations possible at a counter in Berlin for 4.90€. You could also make one online on intercity.pl for the bit within Poland : Rzepin - Krakow -> 1 PLN (0.2€).

Or you could take the alternative route via Warsaw but I don't see any advantage.

Krakow - Munich : I see at 11:10 departure via Breclav and Vienna, is that what you got too? The 6 min transfer in Breclav (15:49 - 15:55) is a bit tight but you've got 2 later trains in case : 16:20 and 16:27. Reservations cost 3€ per train through ÖBB with seat selection for the last leg (at least).

Munich - Knutsford : very long journey with mandatory reservations. Book as soon as possible as it's the Easter weekend!

18€ for the cross-border TGV and 30€ for the Eurostar (2nd class prices). Have at least 1h30 margin in Paris to walk 10 min between stations + clear security and passport controls.

London Euston station will be closed for the Easter weekend due to works. The easy alternative is a train to Sheffield leaving from St. Pancras where Eurostar trains arrive. Planners haven't been updated yet, please use nationalrail.co.uk.

Train 1: The Eurostar website doesn't sell pass reservations, so did you really book a pass reservation and not a regular ticket? Pass reservations London-Amsterdam are €35 in 2nd and €43 in 1st class.

Train 2: There's probably enough space, but a reservation is just €3 in 2nd and free of charge in 1st class on tickets.oebb.at: add the Interrail/Eurail discount and then select "One-way tickets” (NOT "Seat reservation only”).

Train 3: it's actually 2 trains and if you don't want to hang around in Warsaw, then you can be in Kraków by 20:17:

Both trains have mandatory reservations. Berlin-Warsaw cannot be booked online. You can book it in Germany at the ticket office, or you can book it from the first station in Poland, which is Rzepin, on intercity.pl. The second train can also be booked on intercity.pl.

Train 4: this is a journey with 3 trains, departure 11:10, with changes in Breclav and Vienna. The first train has mandatory reservations, which can be booked on tickets.oebb.at The 2nd and 3rd trains have optional reservations, which can also be booked tickets.oebb.at. If you miss the connection in Breclav, then there are later options with which you can still catch the train that arrives in Munich at 22:32.

Train 5: This is a journey with 5 trains. The first 2 have mandatory reservations, which can be booked on raileurope.com. The trains in the UK have optional reservations, which can be booked free of charge on the GRW website.

Also see this overview on how to book reservations:

https://www.seat61.com/interrail-and-eurail-reservations.htm

Finally, please don't use the Eurail website or the rail planner app to plan. They're incomplete, often out of date and unreliable. It's best to use national planners; for international journeys, bahn.com or the DB Navigator app is a good choice.

Sorry I meant for train 1 I got a Eurail seat reservation via SNCB International

for berlin to krakow on oebbtickets, the train:

10:52 - 18:10  says “Ticket not available” will this have to be bought at berlin hbf or how should i understand that message

It's not possible to get this reservation online. You need to buy it at a station. (I'd buy it when arriving in Berlin from Amsterdam.)

There's a special passholder tariff of 4 € for this. 

The reservation is mandatory when crossing the border and needs to be for Germany to Poland (a reservation just from the first polish station as recommended before is not a valid one).

Going without a cross border reservation may result in a fine of 30 € per person since February 1st.

The staff on the trains don't seem to care however, according to reports in DSO.

I didn’t read anything about this the last ten days there? Of course I do know the old stories about it…

But:

The rules are clearly written: mandatory reservation from Frankfurt; passholder tariff; otherwise (now) 30 €. I don’t know if there’s a need to give advice how to break rules or which rules are not that strictly enforced. Not meant personally, just my 2 cents...

So decided on a flight from Munich to Heathrow (arriving at 3:40, giving about at hour to get through customs) , and am looking for trains from heathrow to knutsford (departing after 4:30), but Eurail, GWR, and other british rail sites are all showing different times, any recomendations ore help.

Eurail shows an ideal one from London Heathrow T123 (17:06) to Tottenham Court Rd (17:39)

then 30 minute change time

London Euston (18:13) to Stockport (20:09) Seat resevration required

10 minute change

Stockport (20:19) to Knutsford (20:51)

The Eurail website planner is unreliable and out of date, so what it says is irrelevant. It should therefore never be used to plan. It looks like there are some engineering works on that day (30/3) that Eurail doesn't know about yet.

I'd be inclined to use www.nationalrail.co.uk, unless someone thinks there's a better alternative.

As I had written above : London Euston station is fully closed over the Easter weekend. Here is the official notice : https://www.nationalrail.co.uk/engineering-works/milton-keynes-central-northampton-20240329/

Follow what nationalrail.co.uk advises indeed. Since trains don't require reservations you can remain flexible.

Getting to London St. Pancras is easy :

- Elizabeth Line Heathrow - Farringdon

- Thameslink Farringdon - St. Pancras

Afterwards the route via Sheffield will be the most straightforward but expect busy trains. Seat reservations are free of charge so you could make them on one or two London - Sheffield trains.

As alternatives I can think of direct coaches to Manchester Airport (for example 16:50 Megabus departure) but then the last bit to Knutsford is way harder than it should... replacement bus + train in a weird loop. However someone might be able to pick you up or you take a taxi for 30-40£?

Not the best weekend to travel around the UK I'm afraid...