Thomas;
I have two Savage machines, and me and my staff use them to make literally thousands of chocolate bars regularly. In fact just today I molded up over 400 92g bars with them.
There are a couple of tricks you can use to "Fix" chocolate that you have over-tempered with them. Chocolate globbing up around the agitator is a sign of your water temperature being too low. It is cooling the chocolate too much, and causing it to solidify on the side of the machine. The scraper picks it up, and causes the big lump you are getting.
Trick 1: when cooling (tempering) your chocolate, don't have your water temp in the kettle so cold.
Trick 2:If the chocolate gets too thick in the machine, your working temperature is too low and the chocolate is over-crystalizing. You can thin it out by pouring 4-5 litres into 8 or 10 litre bowl, heating it to 45 degrees over a double boiler and then pouring it back into the machine. That much chocolate at that high of a temperature will not take over-crystalized chocolate out of temper. In fact it will probably only raise the overall temperature of the chocolate, maybe 1 degree F. I do it all the time if we need to temper chocolate quickly. You can do this as often as you like to get the viscosity you are looking for.
One other thing: Higher percentage chocolate (80% through to liquor) that has no lecithin in it will become VERY thick, and is difficult to work with even for someone experienced with those machines. You will find that as you work with chocolate like that, your water jacket temperature will have to be about 3 degrees F LOWER than your working temperature in order to keep your working temperature consistent. Chocolateasviscous as 80% +creates it's own friction and heat as it's being agitated. Having your kettle temperature and working temperature the same will almost always lead to overheated chocolate. Dark Chocolate of lower percentages generally doesn't behave this way at all (at least that's what I have found).
You have chosen to start at the top of the learning curve. Good luck with that. All I can tell you is to expect failure and be patient. I failed lots at first.
Cheers
Brad