Do these performance tips still apply?

programming flash
1

http://www.lostinactionscript.com/blog/index.php/2008/09/28/tips-on-how-to-write-efficient-as3
http://www.lostinactionscript.com/blog/index.php/2008/11/01/tips-on-how-to-write-efficient-as3-part-2/

(since it’s written in 2008 I was thinking that maybe adobe optimized stuff)

especially:
Nulling Array vs. Splicing Array (part 1)
Arguments vs. variable referencing (part 1)
Array push vs. Array index (part 2)
Array emptying - length 0 vs. A new Array (part 2)
Type casting comparison (part 2)

Thanks