The short answer is yes... that's normal.

The 550 motors have a very noticeable "cog" when you turn the shaft due to the strong magnetic field (this is with no power applied). This effectively brakes the motor & drivetrain when you cut the power. Smaller motors have this "cogging" too, but it's not as strong and not quite as noticeable. Since the SW26 drive train doesn't weigh very much, it has very little momentum to overcome, and the motor magnets stop the drive train rotation almost immediately when power is cut. With 1/10 cars, or other applications where gear reduction is used and/or more momemtum must be overcome, this "cogging" or braking effect is not as noticeable.

As far as allen wrenches go... I'd recommend getting a good complete set of metric and standard allen wrenches. I've built RC cars, helicopters, planes, etc. and I've found that there is quite an assortment of metric and standard allen heads in the hardware. Some of them are even oddball sizes that aren't included in most allen wrench sets. I went to Sears hardware and the following sets for about $20 each:

[link=http://www.sears.com/sr/javasr/product.do?cat=Hand+Tools%2C+General+Purpose&pid=0 0946755000&vertical=TOOL&subcat=Hex+Keys&BV_UseBVC ookie=Yes]13 piece Craftsman Metric Set[/link]

[link=http://www.sears.com/sr/javasr/product.do?cat=Hand+Tools%2C+General+Purpose&pid=0 0946754000&vertical=TOOL&subcat=Hex+Keys&BV_UseBVC ookie=Yes]13 piece Craftsman Standard Set[/link]

For grease, I just got some at Walmart, in the auto section, labelled "Marine Grease" (for boat trailers & other marine equipment). I put some in a hobby syringe (with a tapered plastic tip) and just cut the tip back so it would just fit into the stuffing tube. That lets me "spot grease" or inject grease in the stuffing tube or outdrive.