My experiment with this is still rather young. But I'll gladly share with you my thoughts and efforts.

My rifle has a tapered throat designed for breach seating, so that is a variable you may not have to contend with. 

I shoot the "cowboy silhouette" game, which, due to time limitations requires fixed ammo. 

I find that if I thread my RCBS FL resizer die all the way in, and then back it out one full turn, that is my setup. I purchased a BACO custom neck expander plug so I get .002" grip on the bullet. I thread the expander into the press so that I am able to hand seat the bullets past the case mouth. From there I use the seater die to seat the bullet to final OAL.

I arrived at seating depth by trial and error by first seating long, and then slowly seating a bullet deeper in the case so that when chambering a cartridge, the round will slide into the chamber until about .2" of the case head is sticking out of the chamber, and then I press it the rest of the way home with my thumb to center up the bullet in the tapered leade of the chamber, and it appears to be a slip fit in the case. In essence that last little bit of pressure required to chamber the cartridge, combined with the .002" of "grip" on the bullet, allows the bullet to center up in the throat, and slide into the case as far as it needs to go.

Hope I helped some, but the short answer is, I back the FL die out 1 full turn.

I slightly bell my brass, but don't size it, if it came from the rifle it's going back into. Then I set up my seating die to just remove the bell. If it chambers easily in my gun, the bell is removed enough and it's good. I don't work my brass anymore than I have to.

My way is most similar to Stubbicat, but I also use the tiniest bit of belling like Marlinguy sometimes. Very little tension, and a bullet will often pull from the case if I need to remove it prior to firing. (Raise the muzzle if you need to do this,same with breech seated). I have experimented with the totally unsized cases, but they were more inconsistent than the other way. The key seems to be keeping the brass formed to the chamber and the bullet as undeformed as possible while having a little neck tension. Works for me pretty well. 

That brass is still fine to use- even much shorter cases made from  other calibers is suitable. As for the bullets being variously shoved into the case to different depths; that will cause mischief and inconsistency. 
But, to counter it, why not try them just touching the lands? There is no absolute rule that says they have to be jammed way up there- inconsistency is far worse.