We use a separate DKP system for different content in WoW:
Tier 7 for Naxx EoE, OS
Tier 8 for Ulduar
Tier 9 for TOC
Each boss in VoA goes with the Tier system in which it was released.

We are easily able to keep track of this in game by bringing up the GRSS window and choosing which DKP to add and subtract points from.

The problem comes when we upload the GRSS to the Website. It only allows us to pick one Tier system to upload to by default, which is fine if we only do Ulduar in a raid night. But if we start in VoA (Tier 7 and 8) move to ToC (Tier 9) and then move to Ulduar (Tier 8) the officer uploading then either has to upload after each DKP System change, or upload after all raids are finished and then manually edit the raids and loot to add all the points earned and DKP spent for loot into the appropriate DKP system.

So my question/suggestion is for one of the following options:

Either make the GRSS automatically uploads to the DKP system that is selected in game and/or allow a choice (checkbox or drop down menu) with each individual snapshot that is uploaded and each piece of loot.

I also have a second suggestion/request or question. We expect our members to use the calendar to signup/unsign for raids and we cannot find an easy way to track who is actually doing this and then actually showing up when they say they will.

Is it or would it be possible to some how track the percentage on the DKP standings page for those that used the calendar to either sign up OR unsign (just so we know whether to expect them or not) for each raid event that we do DKP for?

I tried looking in the custom DKP column but can't seem to figure out a way to track what I am looking for.

Thanks for considering my suggestions/requests and look forward to your response. If you have any questions or I haven't explained these well, please let me know.

The first issue you mention is something I've thought about, but it is something that would have to be very carefully done to prevent hassles if someone were to accidentally have a different system selected when a snapshot was taken. At the moment, I don't have an easy solution for you.

The second issue is a much more complicated one, and something users have suggested in the past (at least the general idea of integrating the signups with the DKP information). For now, as long as you associate the snapshots with a calendar event, you can click that event on the calendar and select the different options from the drop down box (things like "No Shows", which are signups that didn't attend). Stuff like that does kind of work for your situation, but I admit it's not exactly what you're looking for.