Sorry if this has been asked before, but how does the redirect work with stealth? Do you get to pick new targets for stealth?

See the entry on redirect, p17 of the RR, which specifically addresses this:
 

Thanks!

Hi folks,

Could you please clarify, how exactly redirecting works?

For example: there are three players - 
player_1 - takes "Master of King" title;
player_2 - takes "Master of Lows" title;
player_3 - takes "Crown Regent" title.

player_1 initiated "power challenge" to the player_3.

player_3 redirected the power challenge. 

My question: after redirecting, can player_1 initiates power challenge to the player_2 (according to the titles, player_1 supports player_2)?

And to which of the players can player_1 initiate additional challenge according to title description?

http://thronesdb.com...erence#Redirect

- The challenge is still considered to have been initiated against the original opponent, but it resolves against the new opponent.

- Any effect that would prevent a challenge from being initiated against a player does not prevent a redirected challenge from resolving against that player. (This means that a redirected challenge may resolve against an opponent the attacking player supports.)

Player_1 cannot initiate an additional power challenge, neither against player_2 (because he supports him), nor against player_3 (because he has already initiated a challenge against him).

Player_1 cannot initiate an additional power challenge, neither against player_2 (because he supports him), nor against player_3 (because he has already initiated a challenge against him).

Thanks a lot for the answer