I used to count, but after I ran a couple of batches of brass past 30 loading cycles I stopped worrying about it, and no longer bother. Included among that was plain-vanilla Winchester brass, though I use other brands too, like RWS and Geco, Prvi Partizan, Norma and Hornady. After a few loading cycles I neck anneal.
FWIW I don't tumble my brass either, though the work-hardening effect and wear due to that is likely to be small. I just don't see any point to it, nor to scraping residue out of primer pockets. After a while the cases go a bit brown with patina (which is actually slightly protective) but primer residue doesn't build up and I can't see any measurable effect on reliability or accuracy.
The usual determinant of case life for me is losing the case in the field, or the odd neck split if I've neglected neck annealing. I have had pistol brass which ended up with loose primer pockets, but that brass had had a lot of cycles - to the extent that the headstamps were getting unreadable - so it might have just been wear. As long as the primer pockets hold the primers, the necks aren't split and there's no evidence of incipient separation (which I do check) I can't personally see why I'd toss them.
I don't usually load right to the ragged edge of pressures. I'm more interested in accuracy and reliability than the last few fps of velocity. I also only ever neck size my bottle-necked cases, mostly with Lee Collet dies. I don't full-length size bottlenecked cases, and don't have issues with shoulders moving forward enough to necessitate pushing them back. I think that if you are seeing this it is a product of the way you are sizing them. It should be self-evident that when the fired case comes out of the chamber it must be able to fit back in, and indeed have some clearance, so if it won't chamber easily after you reloaded it, unless it is significantly out of round, it must be due to something you did to it in the reloading process.
I only use a given batch of brass in the one rifle - where I have more than one rifle in a given calibre I keep the brass separate. With rifles with large chambers (such as my Lee Enfields) I take a bit of care on the first firing to ensure they are fire-formed concentrically.
