No, los perros no son bienvenidos en lugares cómo este

Yes that is possible. You can rent near the train station of cascais.

The same places are very close from lisbon.if you want to visit prais da ursa you must walk about 30 or 40 minutes to arrive in the beach the uber you will leave at the main road and after you walk, take the left path is more secure if you go with your family and of course you must have running shoes to cross the path!

We had a private tour (do not miss going to the site it is incredible and beautiful).

If you park the car in the road to Cabo da Roca it's about 10-15 minutes walk until the last parking spot (but I wouldn't recommend to go all the way to this spot and try to park the car because 1. If you gave a small car the road has too many bumps and holes and 2.all the space will be already taken by others). So, when you get to this last parking area choose the LEFT path, it will get you to the beach all right (in about 25 minutes) And do wear comfortable shoes)

fui en auto, no tengo datos del bus

Sinceramente não sei, porque foi em viatura própria! Mas deve haver autocarros, com destino ao cabo da roca que fica relativamente próximo

Hey A stroller would not be possible to navigate over the rocks and it's pretty steep, you would probably need to use your hands sometimes. Have fun!

You can catch the bus from Sintra - takes about 30/40 mins. Can't remember the fare but it isn't very expensive.