Rob, the smaller fly bar paddles will give it less cyclic response, so, in a way it will be easier to fly, but harder to perform loops, rolls, flips etc.
As far as the blade grip bolts. If you have the CNC grips you can use a pencil type soldering iron and put some heat on the bolt to melt the loctite. Not sure how well that would work with the plastic grips though as they might get damaged from the heat.
As for the grips moving slightly, you can change the pressure on the dampeners if you can get the grip bolts off. There are washers on there with a 'step' in them. One way makes for soft dampening, flipping one washer makes harder dampening, and flipping them both makes it hardest dampening. The 550 manual I have is old and doesn't explain it, but I think the newer ones do. If I can find a link to the newest manual I will add it here.
Here is a link to the download page at Gaui. There is a pdf file of the latest 550 manual on the left side, second one down. It shows how to change the dampening pressure by flipping the washers on the spindle shaft bolts. Hope this helps.