I am not familiar with the locks but I will tell you there is a walking path to the lighthouse but it is a very LONG walk from the nature center where it begins. Parking at Discovery Park is very limited also. I suggest you google map it.

We had a car. I would have used Uber if not. It's well worth a visit. Enjoy!

My experience is that the trail mostly follows the road with a defined bike path (both directions) on one side of the street. The road from the Fremont/Ballard area in the direction of the park (Gilman Avenue W) is uphill and though gradual could be challenging.

Yup, lots of parking, but it's a ways to the beach if you are interested in that. Also, right when you get to the beach there is a sign that says NO DOGS, which is a bummer if you have one. However, I have noticed that there are always dogs on the beach anyways.

Discovery Park is very safe during the day. Lots of people, including kids, walking, jogging, biking, especially on a sunny day. We have never seen "homeless" folks in the park.

Yes, beach glass is fine.

You can't park down there unless you get a permit, handicap and people with young children can get a permit however you can have someone drop you off or if you have someone waiting in the car and you don't take long. It is a beautiful lighthouse and I would recommend late day around 6:30-8 pm this time of year.

There is a 1.5 mile, not hour, walk from the nearest parking lot. There are 8 spaces at the lighthouse for which you will need a permit. Generally, they are for those not physically able so an elerdy person or impaired my be able to get a permit at the Visitor's center. you can read all about it and find a phone number by doing a search for Discocvery Park in google. Just follow the links.