I really think that this has a very small chance of success...
There are many staking sites out there already (many of which are struggling at best) and for it to have a chance of survival you will need to reach a 'critical mass' of both profitable players and stakers fairly quickly or it will just die a death. There is an issue as well that getting a site like this going has a certain 'chicken and the egg' conundrum in the fact that you need profitable horses to attract the stakers and you also need stakers to attract the profitable horses that are willing to sell their action publically.
With the type of setup you are looking to do, its actually quite important that the levels of both horses and stakers is relatively balanced as well or you will end with the situation where either the stakers get annoyed because there is too much competition over the few profitable horses there are floating about, or the players will get annoyed because there isn't enough interest in the action they are selling to to bid up the prices to what they feel is an acceptable price for them to sell at...
not taken into account paying a wage no. I think it'd mean I play less poker, but not much less. I think it'd just eat into the time I spend reading blonde and lazing in bed tbh!
I also think you are vastly under estimating the amount of time this venture could take up with even only a few packages being sold a week... Obviously it will depend on the exact packages being sold but you could easily end up averaging 15 - 20 investors per package and the paperwork involved in sending and recieving all those transfers is gonna take time (and be boring as shit for the few $ you may be making).
Another issue that you may find is that when people bid on these packages some of them like to have the option of sending money online which will usually be Pokerstars transfer as its the largest site etc. Once you start transferring around large amounts of $ with comparably limited play you could easily run into restrictions as far as being able to make transfers and cash out (wether its your own money of TPB's). I believe if you can get an affiliate account and drive traffic to Stars through it you may be able to get away with more, as PTP does but thats not something I have any real or solid info on... I believe that you will need to closely check the t's and c's of Stars TOS and have a long conversation from someone inside the company before you will be able to use your own personal account for these transactions as I am pretty sure that if/when they find out they will at least block your account as they have issues with their IOM licensing which states that all players accounts must be solely for the purpose of playing poker and not carrying on a business etc... I can see a bank taking a dim view of all the transactions as well fwiw unless you get one of their tailored accounts which I am sure will include some kind of anal fee... Paypal may seem like an option but it really isn't as they won't have anything to do with poker or gambling (I nearly lost my paypal account over it and was blocked for 6 months etc while it was investigated).
As for offering insurance against grimming by people who have won from their stakes... Just don't. If there was a profitable way of doing it, it would be done by now. I can show you dozens of threads where this exact thing has been talked about and its just not viable.
The overall size of the staking market is also something that you have to take into account. The staking board here has a little action and there is small amounts of action on several other forums and we obviously have the 'big boys' ala 2+2 and chipmeup etc. I fear for this to have a chance at being profitable your going to have to look at getting an unrealistically significant portion of the market and if you even get close to a significant market share your going to have several other sites pop up mimicking your idea as soon as the ev of the idea goes above absolute zero (people will always think that they can do it better)...
May come up with some more thoughts after am done playing etc but my personal opinion is that you shouldn't put another penny or a minutes time into the idea...