Archiving CDs to HD...suggestions?

I have very limited knowledge about this, but I'll put in my two cents for a couple of your questions.

1) & 6) It is my understanding that CD players have some level of error correction that is used when playing music. Essentially, this is the what keeps things from skipping during a shock event. I believe that this applies to rips using certain software, but there is software that yields a bit for bit perfect rip. I'm not sure if it handles it as data rather than audio.

Assuming that you have software that always results in bit for bit perfection then vibrations, power conditioning and other audiophile concerns would not apply. If you're using software that can result in some error corrections, then I'd suspect that large vibrations would have a negative impact, but not much else.

The drive you rip from does not really matter.

Use EAC for a bit perfect extraction and watch the log for errors. I use the test and copy mode. The Accurip database will tell you if your rip matches others. The higher the match the more you can be certain it is bit perfect.

Rip your CDs to either wav files or flac. Personally I compress my files to flac. I also create a cue and sfv file. With 3000 CDs you want to do this right the first time. I personally do not like AAC files.

You can have files on more than one drive. I create 2% par files in case a file becomes corrupt. I also use an online backup service. I also have a few thousand CDs.

1) does the cd drive matter to the rip? or do i just need to use a good software like EAC or the like to ensure an accurate rip?

EAC will ensure the data you rip matches what was originally on the disc. However, I believe EAC is Windows-only. The only OSX equivalent I know of is called "Max". However, I haven't used it, so I cannot vouch for it. Also, the drive doesn't matter per se, as most recent drives will rip at many multiples of the normal CD speed. However, ripping 3000 discs will put a lot of wear and tear on the drive, so you may want one that you can easily replace if the first one dies. I have a Mac Mini as my primary computer and used it to rip about 1000 discs. However, if the drive died I would have been hard pressed to replace it without bringing it to an Apple retailer for service. On a desktop PC, I could have replaced the drive in 15 minutes for US$20.

2) if i rip on a PC, do i have to use a PC in the future, or can i use a Mac against my external music store if it was created under a PC?

You can rip on a PC and play the songs on a Mac, assuming you rip the songs into a format the Mac understands. AppleLossless and FLAC will both work on a Mac, although iTunes works much better with Applelossless (you can get iTunes to play FLAC, but it's a pain).

3) what sort of redundancy is in order? RAID 1? RAID 5? or just another HD the same as the one i plan on playing from, and simply use it as a backup?

After I ripped our discs, I just copied the files to two other external hard drives. One of them stays at our house and gets updated with new music and the other is stored at my parents house. It took a long time to rip all of those discs. If something terrible should happen (fire, burglary), the off-site drive will let me recover that music. It took some time to copy all of that data to the second drive, but the peace of mind was definitely worth the modest time and cost.

4) which uncompressed file format should i use? AAC or something else?

Per Wikipedia

Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates.

If you want lossless, go with AppleLossless or FLAC. My recommendation is AppleLossless. You can easily convert from that to FLAC later if you want to (on a Mac you could use a program called XLD to do so, which is fast and free.)

5)any estimate of how much storage would be required for 3k CDs? or would it be feasible to split my music collection across 2 primary HDs...like A-L, M-Z...which is really asking if playback software can read across multiple drives in one virtual "library"

The simplest way to determine how big of a drive you need is to assume each CD consumes 500 megabytes of space (things originally released on LP will be less, more recent releases will probably be more.) In that case, two CDs equals one gigabyte*. Given the 3000 CDs you're looking to rip, that would mean you would need 1.5 terabytes of storage space. However, using FLAC or AppleLossless would reduce the size of each disc, and therefore mean you could get by with a smaller drive. But given that a two terabyte drive these days is around US$100, there's no reason to skimp, and the extra space will give you room to grow.

5) are rips sensitive to vibrations, power conditioning, etc?

Computers are sensitive to power fluctuations, but using EAC or a similar program will let you ensure the ripped data matches what was on the disc, so you should be OK even if your power isn't perfect.

*To the computer geeks out there, I know a gigabyte isn't 1000 megabytes, but it makes the math simpler for this exercise.

The CD drive does matter because they vary in ability to correct errors and dig info out of scratches. The best ones are the Plextor 760's and 716's. Unfortunately these are not made any more and have to be dug out of EBay etc. Newer Plextors are outsourced gubbage.

Software is important too. EAC is ok but with 3K disks you want something more capable. Take a look at dbpoweramp. This has a lot of capability. There is a batch rip util that will process several rips in parallel depending on the capability of your computer. Basically figure that you can run as many drives in parallel as you have cores.

Getting good metadata is huge, and dbpoweramp lets you set up access to commercial services and edit the data on the fly. This will also attempt to snag album art.

Also I would recommend FLAC as the target format. There is just more software that supports it. Unfortunately the one exception to that rule is Apple, which of course is always pushing their own. Which is why I gave up on them a few years ago. But that is another story.

In any case you don't lose anything converting between lossless formats later. The big thing is to rip to lossless in the first place.

The format isn't that big an issue because there is free software that can interconvert (like XLD on Mac). Just make sure it's a lossless format. I do prefer FLAC because it can take any custom tag name you want.

1T is probably enough for 3000 discs, but since 2T and even 3T drives are available now, I'd just get the biggest drive you can to allow for future growth. I use an external USB drive for backup. For ease of expansion, I use LVM (logical volume management), but that's a unix thing, I'm not sure how that translates to other operating systems. With LVM I can add another drive when I need more space, issue a few commands to add that space to my existing music library, and then it all looks like one big drive.