1- I get the impression that grouping bonus benefits really become worthwhile once you have 3 in the party and really shine at 5. Is 2 in party worth it (when RAF is not a factor)?
Grouping bonus won't be much with just 2 in party. But, if you're questing, the kill quests can be done at same time with both toons in party.

2- Does it make more sense to account transfer my pally off to a new RAF linked account? Even at 59 he should be somewhat viable for some boosting, just not all of SM in one pull right? He's got some decent prot gear now (uther's trinket, blazing rapier, wall of the dead). I'd have to be careful about the configuration of the links, or put him on a separate account unlinked, use him to boost until RAF has expired, then transfer him back and cancel the unlinked account.
If using the pally to boost, he/she should not be on a linked account. Otherwise, you get no triple bonus and then you’d cry.


3- I'm really struggling with the best linking method, whether the chain A>B>C>D>E or in a case like having 3 accounts where both 2 new accounts are linked to my main. I guess the chain is best no matter how many accounts you're talking if I don't care about the mount?
Also depends on how you will spreading out the gifted levels.
X = Boosting Account
A->B
B->C
C->D

A is an existing account and B,C,D are the new RAF’d accounts. My first team is four mages on A, B, C, D. So I’ll be able to give levels to my lock team on A, B, C.

4- Does receiving gifted levels allow one to gift levels in return? Say 3 accounts linked A>B>C. Toon on C hits 60 and gifts 30 levels to a toon on B, going 30 to 60. Assume the toon on B had 15 levels to give to A because he quested to 30. Does he also get 15 more gift levels for A based on the gifts received?
No. The levels need to be earned in order to be able to grant a free level-up. Any leveling done via gifted levels does not earn you any free levels to grant.

5- What would be the most efficient use of the 90 day window for my situation, assuming say 3 accounts? Think I would run 3 shammies to 60 and want to set it up so I could then take the 3 20s I have on main account and quest or boost them to 30, then gift them to 60. A transfer or two I can do, it's the 15*X recurring I worry about.
I’m giving myself 60 days to get as many characters leveled as possible. Then I’ll be transferring my other mains from old accounts to the three new ones and cancelling the old accounts. For the next two months, I’ll have 10 accounts active. I will whittle that down to 5 in 2 months. Give yourself a time limit to get things done so you don’t get carried away with the recurring monthlies.

6- I haven't really digested the referral free time/WoW card thing yet, can I get a link to an idiot's guide? I would probably do the referral emails and set up the accounts and then just buy the battlechest(s) from BestBuy since I commute past one. Again I don't care about the mounts, just what would be the most efficient/longest free ride. I don't mind TBC activating all accounts.
When the referred accounts pay for their first month, the referrer account gets one month free. Log on to Bliz’s site and into your account. Check the recruit a friend section and it will show the people you referred and your rewards (free month or mount, etc).

7- Has anyone tried taking these multi-box teams into places like karazhan? I'd have to think 5 elemental shammies could do a lot of the work, add in an MT, OT, a priest and 2 whoevers.
Lots of folks have taken teams into Kara. A few have single handedly brought an entire team! Of course it’s good to have a proper mix of classes.

8- With the two existing computers I have, what configuration would be best for multi-boxing? Run main toon on the old main box with all the clones on the stronger box? The hardware and software is a tough question with my resources.
Use the best performing computer to run multiple wows. Play around with the video options performance is lagging. Test them out with trial accounts.


9- I'm getting stuck on how many free levels I generate, since on an example A>B>C chain, only the B and C accounts/toons can gift levels, the veteran toon A on main account gets xp but doesn't generate levels?
Correct. If A was not referred by anyone, then there’s no one to give levels to.


10- Are gifted levels not only locked to what account they go to and from, but from which toon? I assume you can't generate free levels with a new character on an account and then switch to a L60 on that acct and use those gifted levels from the 60.
The gifted levels are not locked into a particular toon. You can gift the levels to any toon on the veteran account providing they are of lower level then the gifter.

I’m not sure I follow the 2nd part of the question.

Hmm, maybe I can get my wife to pick up any simple hardware upgrades to the computer for my birthday next month. That's the ticket.
Yes. Do what it takes to get your present early. Whatever it takes…

Anyone got advice for what I could or should do? A team of 3-5 clones would be neat if I could also generate a near-raid ready lock, shammy(s), shadow priest, etc. I don't see multi becoming a vocation, but you never know.
Just do it! My main team is my pally and 4 shams. But I’m using this opportunity to give me all possible options in filling up my party. I also want to get one of each class with 3 different specs at my disposal to fill any party at any time.