>>/863/
Not yet. Best way for now is to load up the search you want to do the big job on with a 'system:limit=4096' or similar, and then do it in manageable chunks.
>>/865/
You can take that limit off if you want. Just clear the rule for the PTR service under network->data->review bandwidth usage.
I think the new default rule is 512MB. It doesn't matter for existing users, and the guy who runs the PTR wants it removed completely, but I still need it for new users for now because of a maintenance initialisation issue. I don't want people processing 2GB of data before first round of idle maintenance kicks in.
It shouldn't matter once you are synced, as most update days are far less than the limits, it just spreads out initial sync over a more easily digestible duration.
For your hashes question, yes, files are not uploaded when you add tags, just hashes. I will never upload anything unless you specifically say it. The theory behind the shy wife scenario is you tag a whole bunch of stuff in the PTR, sharing that with thousands of anons, and then years later the images leak and some lad looks them up and see you helpfully tagged them all with name info.
A client by default comes with a 'my tags' tag service that is local only. You can create more local tag services under services->manage services as well. Any time you enter tags or set up tags to be added with a download using tag import options, you should see 'my tags' listed beside 'PTR' and any other tag services. Those are the different partitions you are putting tags into. 'My tags' is completely private, 'PTR' is shared with everyone.
If you want to add 'favourite' or 'process these wallpapers later' tags, put them in a local tag service like 'my tags'. PTR is best for booru-style tags, entered manually or via a downloader and tag import options.