Hello,

It is indeed possible. But be aware that Spain is quite an Interrail-unfriendly country; there are ways to get hold of the reservations you need (

), but they may not be the most straightforward or the best value. I should probably also point out that long-distance rail service on the western Mediterranean coast (anything between Pisa and Barcelona really) can be quite patchy, so I’m not sure Florence to Barcelona would be possible without a stop in between. There are quite a few very expensive cross-border trains which would be the fastest option on this kind of itinerary, so having a quick read of this guide and similar ones out there (some of them on this forum) https://showmethejourney.com/train-ticket-guides/alternative-routes-from-paris-for-eurail-and-inter-rail-users/ could potentially save you quite a bit of money, particularly if you’re willing to travel at a slightly gentler pace.

Some sectors you mention (I assume you do not intend to make stops in between then) are quite far and not that easy by train-plus they often also incur fairly high surcharges for the RES). As this is still quite some time to come-most will not even yet be possible to RES by now- and if you are not married with trains look into cheap flites (if you do not have an overdose of luggages to carry-this will cost extra).

Firenze-Barca, Mad-Par, perhaps Prahy-Vnz are for that.

Cheap low-cost airlis in EUR are RYANair (cheapest, also worst-DO read very carefully the many remarks about this rather peculiair airline), EasyJet, Vueling, WIZZair. or just use google-flites,.

IF you have not yet booked a airticket Chile-EUR-ask a well-known tr-agent on how to add several sectors on the main airline as this may work out also a lot cheaper.