Cool! Thanks so much for your kind words. I'm glad you had fun with my stuff. Happy building!

Wow.. You are an ace.. That was a crystal clear explanation.. Thanks a ton.. Also, I would like to say that I love your Maps and have been playing only in them..!! Its wonderful chatting with you.. Thanks again..!!

What I do for the stand-alone piers is zone the quay area where the pier will be placed as a Parklife park (special zoning panel). If you need a visual example, in the savegame open the Parklife info panel. You'll see how several Parklife parks' zoning expands past the actual enclosed parks and goes out to the quays and all the items in the harbor. Tip, if you include an item like a regular pier inside the Parklife zoning, the regular piers don't have to be behind an entry gate. They'll just need a path or road that's close enough so that the "not connected to road" symbol goes away. I use Move It for that.

Hi! No fear, I am here! There are likely no comments because this isn't the save game WS item, but look at the bright side: you have this space for yourself! So, that sounds like the Parkify Mod. It's helpful for placing any park item into a ParkLife park (that's a lot of "park" in one sentence), but it causes this glitch you're describing if you're trying to place a regular park item outside a zoned park that is away from a road.
Solution for piers:

Firstly, I would like to say that I'm in love with your Savegame.
And then, I should say I'm surprised why there are no comments here.! I was really worried if you were really reading these or deleting them. Anyhow, I came across one really impressive aspect in your city while I was trying to learn how to recreate it. The piers connected to the Quays don't have road access and they arent even displaying a 'Connect to a Road Sign". But when I placed a quay somewhere else without a road connection and tried to place a pier on the quay, it either isn't allowing me by displaying a message " either place it in a park or place with road connection"... Can you please explain the trick or if some mod is responsible for it ?