Raiders ran away all the time. So did others...
I agree about the detection. An NPC should go to your last sighted area, in FO3 they alawys knew exactly whre you were.
I really hope alot of the ridiculous perks don't return:
Off the top of my head:
Almost Perfect - WWWAAAY ridiculous.
Grim Reper Sprint - fun little perk but it made fights insanely easy.
Quantum Chemist (this was a lousy solution to a problem, this should be done through crafting - not a perk)
Animal Friend NEEDS to be waaay lower on the level requirement if it returns, by level 10 and the subsequent levels that are requried to max out animal friend you don't really need it any more. (atleast I thought so)
Karma perks - not bad just silly.
I don't remember what they are all called but several of the radiation releated perks weren't useful or just didn't make sense. (lead belly was great though)
There's others but I just can't remember them.
Like the lockpick one and the hacking one were silly...
It should be a standard part of the game. NOT a perk