I think there is a lot of bolting things together with a Lumber Mate, isn't there? Logs are heavy and steel is steel, with most things connected by nuts and bolts, you may find yourself tweaking it from time to time. Mine has so many adjustments, I could spent hours wrenching on it. I mainly make sure the bed is level end to end, bunks are square to the dogs and the blade guides are adjusted within tolerance to the bunks, then set my indicator to the rulers. I don't mess much with the head tilt, but I do make sure the head rollers are adjusted tight enough to the roller bars which are welded to the frame.
I doubt you have a bent frame if that's what your worried about, if so any good machine shop will be able to straighten it for you. One thing you may want to check is your frame flex with a big ole log on it. Make sure you don't have any weak spots in the steel like a stress crack or loose bolts. Stress cracks can be welded and loose bolts tightened, bend frame members can be replaced or straightened. So no worries man, any mill is just a big bucket of bolts and a lot of steel, Like any other machine it's going to require maintance from time to time. The more you run it the more it will need to be maintained. There may even come a day when you have to do a little welding on it and just wait till you get enough hours on it and things start wearing out, like bearings and seals. Consider it part of routine maintance and the cost of doing business, factor in your time, parts and the cost of maintance into the price of your product and you'll cover yourself without much surprises.
I have to admit, I learned my lesson the hard way. Lets just say a broken drive side shaft caused by a piece of yard tree log trash buried deep in a ole hickory log was no picnic to repair...
Thanks