~Are there any ADR's to be made? How far in advance should they be made?
I have never made them way before. The earliest I have made reservations was at 7.30 pm for a 9 pm dinner. Unless you want to have dinner on New Year's Eve, Christmas Eve, New Year or Christmas (and maybe Valentine's day), I don't think they are necessary. If you are with a LARGE group, make them on teh day itself, at teh restaurant directly or at City Hall. At City Hall, they also have a copy of the menu's, so you can have a look at them (and the prices!)
~Any secrets to navigating through the park when crowded?
The most crowded I have ever seen the parks was last year the weekend before Christmas, and even that wasn't the worst thing in the world. I wouldn't worry too much about it.
Next to that, I think DLP is easier to navigate than DL, mainly because of the Arcades on Main Street, and because somehow, the rides are more all over the place. You don't get too many bottlenecks. They also don't have fireworks or Fantasmic! or so, the only time Main Street gets a little crowded is after Fantillusion, when everyone wants to leave. Just go on another ride or go shopping, and after that you'll be fine!
Must admit I haven't been looking for them.
~Souvieniers that are a must?
That depends WHAT you like. They do have CDs with parade-music, which I like. They have the wonderful book "
Disneyland Paris - From Sketch to Reality", which IMO is a must for every DLP-fan.
They have nice home decor-stuff (tableware, kitchen stuff, bathroom stuff. I plan on buying some canisters, the white-with-blue ones which have the most wonderful picture of Minnie making cookies. If they still sell that one.)
~Best place to watch parades?
In front of the Photo shop or in the Castle Theater (or however that stage is called)
~How about your best insider tip in general?
There is that other thread that covers this.
At DLP, people (almost) never queue for Character pictures, and they do queue for rides in the wrong place. Just ask whether you are in the right queue. (No use waiting half an hour for Belle's Christmas show when you actually want to go on Casey Jr.)