10 day Europe trip

You want to do a lot in just ten days. I don't think you would like it.

Suggestions welcome, which is the place I can chuck out or add-in based on geography with context for our travel ease.

You haven't given any clues as to your interests, so it's difficult to advise. Ten days means 9 nights.

Paris is a big hitter and you could easily spend a week there and deserves 5 nights as a minimum. Amsterdam can mostly be covered in 3 full days ie 4 nights. That fills your 9 nights. Take the train between the cities.

Or

6 nights in Rome and 3 in Venice or Florence. Train or fly.

You certainly don't have time for 2 cities and 2 whole countries as you have currently planned.

Late March is not a good time for the Alps if spring comes early. Paris and Amsterdam are classic destinations, very different from each other and from London. And it's only about a 4 hour train ride. There are lots of day trip options from both Paris and A'dam.

Appreciate your suggestions, thanks.

How about Paris and Switzerland, for 5 days each which is wat we are really interested in, what you reckon??

Or should I go for Wat Jennifer suggests Rome & Venice

Well, if Paris and Switzerland is what you are interested in, it doesn't make much sense to go to Rome and Venice. :-)

Make sure you count your travel days and nights correctly: Are March 23 and April 1 your departure and arrival dates?
That would leave you with 9 nights = 8 full days in between. IMO, that is barely enough for one of those destinations you have chosen.

Fly into Paris out of Zurich or Geneva or vice versa. Commit and nail the airfare down first and then we can help you fill out the rest

But don't count on good weather in Switzerland that time of year. I'd stick to Paris and Amsterdam, or to Italy. Spend some time looking at guidebooks and figuring out what you actually want to see and do. Try to fly into one city and back from another to save backtracking. And don't delay, as March is coming up fast.

Is your interest in Switzerland the mountains? Or the snow? Or the horse racing on the lake at Sankt Moritz? Or the lakes? Or the cities of Luzern, Zürich or Bern?

Are you hoping for skiing or hiking?

I would do Amsterdam and Paris OR Paris and somewhere in Switzerland. Three places is far too much for 10 days. I would vote for Paris / Switzerland. Paris has a lot to see and Switzerland has beautiful areas. You can easily fill 3-5 days in each place.

Switzerland isn't exactly a "place". It's a whole country.

Nigel is perfectly right in asking what the OP wants to see in Switzerland. If you visit Switzerland without knowing where you're going and what you want to see, you better have at least six weeks.

Not to mention a great deal of money.