Multisig with same keys is it possible to make a multisig tx with the same keys ?
For example, i got:
Key A, Key B, Key C

Now A should be able to spend the coins and also B with the help of C. (B and C alone should not be able to spend the coins)
So 2 keys out of 4 should work but can key 1 and 2 be A (AABC) ?

Thanks,
A transaction of the form:

2 pubkeyA pubkeyA pubkeyB pubkeyC 4 OP_CHECKMULTISIG


should do what you want. Give it a try on testnet, shouldn't be hard to whip up a test case using the raw transactions API of Bitcoin Core.