Needs the pins ANT and INT to be wired on M1-mini to use the internal antenna?
Short answer: no
Long answer:
The (integrated) internal antenna is enabled when shipped. If you wish to use an external antenna, then Cseries should be removed. Leave Cseries populated if you wish to use the internal antenna.
There is an advanced configuration we don't normally advise because of the complexity: the M1-mini can actually be set-up for both internal and external antenna use (with wired ANT and INT). In that case, the 2 antennas need to be tuned together which causes lots of difficulty because the 2 fields are being coupled.
How can I verify the correct setup of a JSR-82 implementation (avetanaBT, BlueCove etc.)?
Use following lines in Java to get the hardware address of your Bluetooth device:
LocalDevice local = LocalDevice.getLocalDevice();
System.out.println("Local BT Address: " + local.getBluetoothAddress());
If this lines prints out a valid address (i.e. not a zero-filled string), the implementation has access to the Bluetooth stack and the setup resp. the implementation is working.