I have read a number of books on susp design, setup my autox car so many different ways its embarrassing to describe some of the weird handling I've caused, autoxed on a number of surfaces at all levels of competition. Really, it's a learning process, and I've learned from my trials and errors. I have coilovers in front only, and while you are right that crossweights can be adjusted (I've done the cornerweighting thing too) it still comes down to how well the front of the car sticks vs. the rear, on the road, not at the alignment shop. I change the f/r balance by raising BOTH front corners of the car. Many people forget about that option. I once dropped the rear, raised the front a bunch, hit the autox course, and promptly understeered (pushed) right off the first corner. It was awful. Great extreme example. Get the cornerweights balanced, but the whole front end can go up or down. I get my rear up and down via different springs or spacers.
As for the inside rear wheel spin with a LSD, unless you have a fully locked rear end, if the LSD is original and worn out (most are) the inside wheel will spin (just like an open diff). The stock LSD units had a fairly low % of lockup anyway. Get a aftermarket clutch unit, or helical gear unit like a Quaiff or the TruTrac, and they will work great as long as there is some resistance on both tires. If the inside tire lifts off the ground, it will spin like an open diff too (I've done this with the TruTrac). Not a fault of the LSD, its working as intended. So, the goal is to have the rear tires stay in contact with the ground on corner exits under extreme power. Not an easy task with our cars. Eibach and such maintain a fairly "nose down" balance. There are many that want the front down even more. Thats fine for drag racing, ok for street, but won't give you the best handling in turns. Selection of sway bars is again a balance of front to rear grip. Terms like understeer and oversteer get tossed around like passengers in my car. Keep in mind that if your car is at max grip in front, yes, a stiffer bar will cause understeer. I am still looking for max grip in front. Two things I focused on when trying to solve the rear traction problem: 1) decrease outside front corner compression on corner exits. It causes the inside rear tire to lift. 2) lower the rear relative to the front, or in my case, it was easier to spin my coilovers one turn higher on both front corners. There is just so much front susp stuff going on in turns, camber, toe, static or at speed. We have nose heavy cars, and despite a f/r weight balance of approx 53%f/47%r , I have had to really tweak the susp setup to get improved competitive handling.
Most folks won't get the full enjoyment of the TruTrac LSD until the traction problem is addressed. Better than stock, yes, but so much more is available. Ok, I've rambled enough. Just my opinion, another $0.02