Linked Lists questions

1 Im making LinkedLists with two empty objects, one in the beginning and another in the end,does it make some difference in speed if the first one is like
var next:*;
instead of
var next:sameObjectType;

2 How can i sort a Linked List?And dont answer ‘google it’ because i did it already, tons of links and no good explanation.The best one was the polygonal labs way but he just add the method to his linkedlist class instead of explain how its done.
I dont want to use other ppls code, i want to UNDERSTAND how its done.

3 Sometimes i want to use LinkedLists but i end up using arrays because they have an index to identify each item, is there any workaround to solve that with LinkedLists?
( Im thinking on use an identifier property on each item but that would make pretty much the same as the array isnt it, i mean, gotta have to iterate in all the list updating the index when add/remove some item, and i supose linkedlists speed cames from not having to do that)