Tickets are needed to the best of my knowledge. we went at 11:00 AM local time on a Tuesday in early May and it wasn't too crowded.

I doubt it. All entrances were gated and probably aren't opened until 9.30am

I think you can

Buongiorno, In risposta alla sua domanda, a causa delle caratteristiche architettoniche del Park Güell, le persone con mobilità ridotta possono avere difficoltà a muoversi a causa dei sentieri irregolari e dei pendii ripidi. Vi consigliamo di visitare il nostro sito ufficiale per vedere i percorsi consigliati nella sezione "Pianifica la tua visita / Accessibilità". Cordiali saluti.

La fermata e' LESSEPS sulla linea verde L3

We bought tickets at entrance.

Yes. Restrooms outside the main entrance, inside the park and inside by the exits.

Good morning, In regards to your request, we inform you that people with pets will be allowed to enter, provided that the pet is kept on a lead (in compliance with the environmental byelaw of 2011). Visitors can access the entire park with their pets, except for Nature Square, Hipostyle Room, the Dragon Stairway, the Austria Gardens and the Laundry Room Portico to ensure the safety and protection of people, pets and heritage. People who own or accompany pets shall be responsible for any damage that those animals may cause. You will find this and other useful information in our website. Kind regards. Visitor Attention Service

Good morning, In regards to your request, we inform you that the following times are reserved exclusively for neighbors and Gaudir Més members, and tourist visits are not allowed: "BON DIA BARCELONA": From 7:00 h to 9:30 h. "BON VESPRE BARCELONA": From 20:00 h to 22:00 h. Kind regards,