Lee
As the owner of both a G-11 and GM-8 for quite a number of years, you
WILL need to become familiar with the workings of the mount. I would suggest that you join the Losmandy Yahoo Group, in their archives is an enormous amount of information from a lot of very experienced people.
As you have fiddled with the worm, I would suggest that you use the hand paddle and slew to the safety stops in either direction to make sure you haven't tightened the worm on another hight spot or that you have loosened it to much, there is a fine balance between over/under correcting the worm and having a lot of backlash.
The newer G-11 and GM-8 have a different grease now so you should have no need to change that.
As you have a Gemini, I would suggest that you become familiar with it prior to going out under the stars, there are a few new user traps that will get you. You can set it up in your house or garage and slew to targets etc. As already said, check the Gemini and load your mount parameters, Lat and Long, Timezone, UTC Time (important).
As you have found out, the G-11/Gemini combination is sensitive to power requirements, I use a 13.8/10 amp GME power supply with no problems. Just about any problem with the Gemini Unit can be traced back to the CMOS battery so be aware of that.
Have fun learning
Cheers
JohnG