Firstly changing the baud rate on the Bluetooth RFCOMM / Serial Port protocol should not make a difference, since it is not a real serial port but just an emulation. (Specific manufacturers could so something special with it but Bluetooth in general or Android does not use the parameter to control over the air bit rates)
The factors that effect the data rate over SPP will be the size of the packets, the practical max data rate you can get over Bluetooth and how fast the receiver is reading / and how frequently the sender is sending. For the packet size you could look at internal documentations or try different sizes to reach an optimal number for your application. Also I would suggest sending multiple packets (or all) until the stream can send data continuously, similarly read continuously.
The main issue here for you seems to be the practical throuput you can achieve over Bluetooth. If you are using the non-EDR versions as you have mentioned in your question the theoretical speed at the very low level is 720Kbps , and adding protocol and application over heads as well as RFCOMM protocol overhead you could get max around 450-500 Kbps.
If you have access to both devices that are +EDR I.e Bluetooth version 2.0 or more + EDR then you can expect application throuput in the order of 1.2 to 1.5 Mbps ( theoretical over the air bit rate being 2.0 or 3.0 Mbps)