just got back from spain this summer... it was a fun trip and did LOTS of flying..
you need to go to the spanish aviation administrations website, there is one in english.. and print out the rules (and carry them with you)
you need to go to TSA's website and the EU equivalent and print out the RULES and (you guessed it carry it on you with your hardware through the airport)
there are more rules over in spain.. but they were not too painful.. your bird is over weight so you will be restricted, airports, city, flight over people, etc. BE SMART... don't stand out as an easy target.. i.e. don't launch in a crowded central plaza over 100's of tourists and locals sitting in open cafes enjoying a tinto or coffee... BE DESCRETE...
as for travel.. part of the print out rules (FAA/AIRLINE/EU) specify battery sizes.. PRINT OUT the DJI spec page for your batteries.. and (carry it with you) .. YOU ABSOLUTELY CAN NOT CHECK BATTERIES .. PERIOD .. you have to hand carry. the drone can go down below but without batteries.. I hand carried everything .. I didn't need lipo bags either.. in fact, I had my spark batteries sitting in the charging station with the drone. (batteries can't be connected) and nobody batted an eye
basically, when you are challenged, it will be by someone that likely does not know the rules, be the smartest person in the conversation, keep your cool, and show them printed documents.. you win..
keep in mind the spanish have multiple levels of police, local through federal.. the federal guys are not to be trifled with.. be polite with all of them and remember .. speaking louder does not equate to better translation, be calm, quiet, humble, and show them that you have at least tried to do your homework by .. you guessed it, showing them all the printed rules and how you were doing your best to follow them..
I never got hassled ..
a good starting link...
Drone Laws in Spain | UAV Coach (2019)
remember that the spoon that feeds you should be in your hands not mine....