so, i installed NEM, created a real data account and transfer the stake from NXT AE with the encrypted message of my real data NEM account (N....)
and now

i'm still logged in with another NEM account (T....). When and how do i see my NEMs in my wallet and can start with harvesting?
Now you can check if you have successfully registered here (use ctrl-f to find easier):
https://chain.nem.ninja/stakes/registeredYes, it is normal to still have anly T (test) addresses and "account" since real NEMs haven't yet been released.
If you want to test the system you can do that by using testNEMs. Just put your testNEM address in the signature or go to official forum and request it there:
https://forum.nemcoin.com/index.php?topic=2547.0You can harvest with testNEMs but it is all just for testing for now.
Further instructions/info will be posted soon. Please check frequently this thread as well as other resources:
thanks for this useful information.