I don't have a LA, but I do have a semi-industrial 9" machine (Pfaff GrandQuilter) in a frame.
1. Go slow. Take your time. I have problems with this still.
2. I don't generally have tension issues, unless I screwed up the threading. On the LA's, I really don't know the answer to this.
3. The stitch regulator helps keep the stitch length consistent regardless of the speed of the machine. Once it is properly calibrated, it makes all the difference in the world! I can't imagine *not* using mine!
4. At first I thought I was insane for having dropped the money on my setup, even though I got a great deal on a used one. A LA is a MUCH different investment from my setup, however, so not sure my experience is helpful here.
5. How much do you spend sending your quilts out to be done by a LA'er? How many quilts do you do a year? Do you think you might someday quilt for hire, even if you don't intend it to be a significant source of income? Depending on the cost of the system you're looking at, your answer may be yes, it may be no. If you're looking at a $9k used or basic system, I'd say absolutely. If you're looking at a $25k Gammill or AQPS? Maybe not, but only you can answer that.