My wife and I will be traveling in Europe for three weeks from mid-April to mid-May. I have already

My wife and I will be traveling in Europe for three weeks from mid-April to mid-May. I have already got our round trip ticket to Amsterdam and lodging there, plus in Florence and Croatia. We're really looking forward to this. I have a couple questions that are probably easy for some of you experienced European travelers.
For our AMS-FLR-DBV-AMS flights I have found Skyscanner to do a pretty comprehensive job with reasonable fares compared to other sites. I have never used them before. Have others had experience cruceros celebrity cruises with Skyscanner, and are there any better options?
It seems for some legs of our itinerary a one-way flight cruceros celebrity cruises is about the same price as a round trip. Is there any way to book AMS-FLR-DBV-AMS all in one shot and get a better price than doing each leg separately? I haven't seen a way to do this on Skyscanner.
Skyscanner is just an online travel agent similar to Expedia. What airlines are they suggesting for AMS/FLR, etc.? There are a lot of budget airlines in Europe and round trip isn't always cheaper like US airlines. One way tickets cruceros celebrity cruises can be quite cheap. Find the airlines that fly each of your legs and book directly with them.
Both Skyscanner and Whichbudget put you in touch with the airlines' own websites as well as agencies. They connect with more Europe-based lines than such big international sites as Kayak, Orbitz, Cheapoair and so on. You can certainly run the combination you suggested through any of them, probably finding a certain amount of variation each time. Do the comparisons yourself. Like the previous poster, I always go for multi-city itineraries rather than flying into and out of the same gateway airport.
cruceros celebrity cruises Thanks for your ideas. cruceros celebrity cruises I'll check the airline sites and see what they offer, but expect it will be the same. Lufthansa, SwissAir, Croatia Airlines are some that come up. There are some budget airlines as well, including a Spanish one, but the layover times are ridiculous.