doublevr You won't stop piracy by introducing stricter download limits. You reduce piracy by offering users a more comfortable solution worth paying for.
For streaming users, this is already done with meta data, such as cue points, searching for other scenes of the same model, and the ease of use without the need for hard disc space.
For download users, on the other hand, it runs in the opposite direction and the convenience of torrents increases with every further restriction by SLR.
If it's more convenient to download files per torrent than on the official site, even users who are still on the fence will turn to torrents. And stricter download limits are are step in that direction.
Why should limits prevent a "siterip"? You don't have to download all files every time, only the newly added files. In the worst case, several users share the download task - but that would only be necessary if there are more new files than the download limit covers - and at that point you are already alienating a large number of regular users.
Also, the download limits actually increase interest in "siterips" because it takes far too long to download even a single small studio's videos. If someone discovers an interesting new studio with, say, 100 scenes, with your new limits it would take a month of micromanagement to download those 100 scenes while keeping up with SLR Originals and some other videos. The pirate opens his favorite tracker website and is done within a day and a few minutes of "actual work" if his internet connection is fast enough.