Depends if its a 3DS Action Replay or not. If it isn't then no, If it is then yes.
Yes you can get DS codes on a Action Replay 3DS.
NO.
You need an Action Replay 3DS, other versions won't work on it - note that it is built to work on regular DS games, there isn't a device for actual 3DS games yet.
A 3DS action replay has never been announced by the people who made the DS action replay.
Answer: Action Replay does work for the 3DS console, but as of right now (24 July 2013) no 3DS games are compatible with the Action Replay 3DS due to hacking problems. You can still use it on regular DS games but not on the current 3DS games. To sum up my answer the answer is yes and no.
No, you will need a different format of Action Replay, which will be more expensive. BUT you can use your action replay DS with it for your DS games the action replay DSi is not compatible for some odd reason -_-
The R4 has Action Replay built-in with the firmware, so there's no point putting an R4 into the Action Replay.
yes action replay dsi will work on ds and ds lite. however, action replay ds will not work on dsi. :-)
The DS and DSi Action Replay both work on the Nintendo DS, But the DS Action Replay doesn't work on DSi.
No. Of course the action replay doesn't
No, the 3DS will not recognise it as an authorised device.