I'm just going to pop in since there is all the talk of ROI and individual payouts. I'm nobody, a lurker, a miner. So these are just thoughts from a semi outside perspective.
The idea that was behind this thread and the thread title are outstanding concepts. The idea of multi-sig fund management is an amazing concept, it starts to diverge when it becomes a group buy scenario. Group buying mining units, group buying hosting, escrow for purchase, a different escrow for hosting. It holds a lot of trust in certain individuals, unless this is all part of the OP post 4-6 multi-sig account as the escrow holders, but I see no mention of that specifically, perhaps it is just assumed.
The idea of a true mining co-op is astonishing. Incorporated as a mining firm, with eyes set on the future. Elected board members from across the world using multi-sig funds to conduct business on behalf of the co-op, with individual hash power as voters in the incorporated co-op business. Elected members donating time to the duties of the co-op to better every share holder, think secretary, treasurer, business manager.
Moving beyond individual ROI to the betterment and growth of the Co-Op and reinvestment of funds to expand, both in mining capacity and revenue streams. Building out or implementing blockchain related services (driveshare storj, micropayment systems, own datacenter/hosting).
Shares can be bought and sold, and include the voting rights, with additional expansions adding shares. Share holders would receive small profits from the additional sales and revenue on agreed upon time segments.
Voted upon bylaws and directives. A miniature bitcoin system with consensus, share holders deciding what is best to move the Co-Op further along, or flat out end and split revenue.
This is somewhat how my electric company operates, they have a semi monopoly on the area of course, but every user is a voting member of the co-op and extra profits are sent out every few years (it amounts to nothing $23 since 2006), but the larger users get a larger portion, and we all have voting rights at share holder meetings, and each have a vote on our board members.
I just think, if you are going to go for, go for. If you are putting your money into something just to get a few dollars off, that's thinking of the short game. If you are investing in yourselves, this technology, and the future there are many paths to choose. Starting a co-op that could become a payment processor for the future, a data center for the next generation, and at the same time increase revenue while cutting costs is a titillating idea.
It's late, I'm red-bulled up, I apologize.
Yeah I can deal with your concepts above also. My calcs were just 'napkin jottings'. But yeah there is more to such a notion then 'just' ROI. So yes I agree. Then again I always thought that my home miner operation would have been a hell of a lot more fun with 4 or more folk locally. It could be bigger (better toys)...less risk (better toys)....and someone to shoot the shit with about this crypto stuff...(did I mention better toys) ....I ran a big bbs game server Lost Gonzo BBS with 4 sysops..was a lot of fun..(dos etc) when one of the Sysops cracked in frustration and tried to toss the server off the roof we could talk him down...heh a lot of fun. Alas only 'foo...' er I mean 'enlightened type' to do this in my area. I know my friends have planned an 'intervention' when they know bitcoin will go all 'ponzi' and have to 'de-program me as a dang btc moonie" ...alas I keep making money and they are confused (their heart is in the right place .but still lonely in crypto land around here)
So yeah your scenario works if for no other reason at least it is a group effort even if 'virtual' in nature....and hell I can still drink beer on my couch with you all via Skype..so wtf it probably will work if BTC price and difficulty let the kite get off the ground

I've done everything WRONG since being a newbie in 2013 and still as of now am $11.5k usd ahead of last month with the price pop and still mining (setup: lostgonzo.imgur.com) so wtf newbie stupid and clueless seems to have worked so far. I'm ripe for a 'virtual' endeavor. Assuming we can get all the ducks in a row that is.
Side note: I'm a legal miner in the USA (don't ask it is a long story) but I probably can get whatever eguip I am responsible for at 25% equip deduction...assuming you run the biz at a profit for 5 years (I'll be at 4 in 2016) ...with (last I looked) 1/2 the equip depreciation off taxes the first year..so folk MAY want to look at how legit they want to run this.me I have NO choice...but mining ..even virtually these last 2 years would help me lots ..from the last 3 years...so may be worth the risk in my case just for the bona fides of such with the IRS showing I'm in it for the long haul all 5 years etc..anyway for those who may also be in a similar boat.caught in the 2013 IRS Guidelines (my bank had an error said i sent $99k (i sent $10k) overseas....to KNC....got all up in the air ..(btc was evil in 2013) i filed just in case...pointed out bank error....the bank tried to screw me saying i was not a legit biz...had the CPA biz modified tax forms to shut them down...figured they do that to save face ..was correct..so far have paid NO taxes due to 2014 lag and equip i got (kinda went overboard on equip)
anyway..thus WHY I'm a legal miner the rest of you run for the hills thou..I got caught (again seems to all gonna work out even steven thru luck thou...so can't complain...knock wood...er I mean $$$ to tax man wise a wash)..but the rest of you head for the hills (unless this mining co-op may also work for you legal in my manner)
anyway tangled webs ..but this co-op may serve my needs better then most anything else for miners etc and showing IRS I still be legit into 2017.