Hi 222sm, welcome to the forum !
I have a saffire 56 as my audio interface. I mainly use it for the ADAT transfer for my external units and use the internal preamps as if I need more input.

I'm assuming you actually record with the yamaha and want to use a computer instead.
If it's the case think twice about using a computer for live recording. The failling rate and instablilty risks are higher than a harware solutions.
If you are recording very sensitive material and can't afford to fail. I'd look for an harware solution.

I know it's not in the same price range but if I was ask to record every show of a tour, I'd go with a harware solution
Like the http://www.sweetwater.com/store/detail/X48MKII/ with the optional ADAT cards

Anyway, back to the saffire.
It's a capable unit and can handle your needs. One thing that makes me question your approach is if you take the direct outs of the main mixer or the monitoring mixer to record via the Saffire, you're gonna send the signal from a preamp to a preamp. Because the line ins are not direct connections to the converters. We should research this but the AD3000 may be built the same way. I'm sure there is some multi channel converters that could be cleaner then this preamp to preamp signal path. (maybe someone will step up to help us on this) ;)
All in all, you want to read the compatibility list to choose your firewire adapter :
http://global.focusrite.com/answerbase/is-my-firewire-device-compatible-with-my-firewire-adapter

Daw choices are wide and get from free to expensive. Samplitude is regarded as sonicly clean DAW. You should demo a few and judge by yourself

Assuming your 01V96 has the MY16-AT option card installed, the Liquid Saffire 56 will get you 16 ADAT channels into a computer. I wasn't clear about how you were proposing to deal with the additional 8 channels: were these to go via the Saffire analog inputs (to make 24 channels into the computer) but also routed via a Saffire ADAT output back into the 01V96 for live use? This setup would be fine for the live sound, especially if you use the 8 Saffire inputs as your "money" channels, but it does not address the recording question.

We have had many threads in these forums over the last few years about the pros and cons of using computers for live multitrack (e.g. more than 16 tracks) recording, and people seem to fall into one of two camps. Either they say that they have never had a problem with using a computer for large numbers of tracks and trust it implicitly, or else they say that it's too risky and instead use a dedicated recorder that is not susceptible to the common computer recording problems. I declare my hand and say that I'm firmly in the second camp, and have been recording to dedicated hard disk recorders for the last ten years or so, but have no problem with others who trust computer recording. There are, of course, a few who do both as a safey measure.

What should you do? If you are thinking of the Saffire principally in order to improve your sound quality over that achievable using either the 01V96 pre-amps or (especially) those in the ADA8000s, then that's a good objective. However, there is quite a wide choice in that section of the market, and you should consider carefully which product to invest in. On the other hand, if going for a Saffire is mainly to get multitrack recording, then there are other ways of achieving that end, and your consideration should be at a higher level: how do I best run 24-channel live sound while recording all the tracks? Have you looked at something like the [[url=http://[/URL]="http://www.rme-audi…"]RME Fireface UFX[/]="http://www.rme-audi…"]RME Fireface UFX[/] which acts as a computer interface but also will record directly to a USB memory stick or plug-in USB disk drive?