I have a grip and eliminated the shutter speed / focussing issues by setting all to manual. In any case the info button displays the maximum frame rate on the back LCD. It looks like it was supplied with EL3e batteries which, even with the grip, can only go up to 5 fps. For a higher rate, it's the grip plus EL4a or AA batteries.
I wouldn't worry about disabling the shutter speed / focusing stuff. You need that to take a picture so keep it how you have it.
The grip WILL boost you up to 7fps IF you have the right shooting mode. Check on the top left of your camera and change the "Release Mode" dial to Ch(Continuous High Speed). There is that release mode dial release button that you need to press down in order to turn it and that dial is underneath the WB, QUAL buttons.
There are a bunch of options there. You have CH and CL (continuous low), Mup (Mirror Lock up), Timer and a single shot. I am guessing that you have the camera set to single shot.
CH is where it is at in order to get the fast FPS. Of course, if you have your custom settings for the "Focus Modes" like S (single) or C (continuous) set to shutter release only upon focus then that could also mess up your FPS rate.
Custom Settings a1: AF-C set to release + focus. Use this for moving subjects. a2: AF-S set to whatever you want for single shots. Use this for portratis. I have mine set to focus only because everything is static and the subject won't be buzzing all around me.
d4: CL Mode Shooting Speed will allow you to set the low speed shots when you need faster than one shot but less than the 8 fps. It defaulys to 3 FPS I boosed mine up to 5.
CH speed will be as fast as the camera is able so it will change with a grip without a grip and with the better D3 battery up to 8.
So you need the MB-10 Battery Pack, the camera set to CH to acquire 7fps and then the EL4a D3 Battery + the Nikon BL-3 Battery chamber cover so it fits inside the MB-10 pack.
I haven't verified it myself, but one person was getting just over 8fps by using single shot mode and pressing the shutter VERY rapidly. I think I would get a finger cramp that way! But you might try that, and see if it works for you.