Can I have a facts of life discussion with you for a second?

I enjoy giving money to charity. I also enjoy investing. Your proposal is not competitive with the investment options available to anyone with a substantial amount of money burning a hole in their pocket. (For that matter, your investment is not competitive with investment options available to me, and I'm just a middle class American who is capable of using the computer and a discount brokerage.)

For example, take TIPs. They're backed by the full faith and credit of the US government, not somebody who will retire eventually and may be hit by a bus tomorrow. They pay out 3.785% of $300k (annually), rather than 3% of a number which is likely to be substantially less than $300k (annually). That starts accruing tomorrow, rather than whenever the US government gets a paying job.

They are liquid -- there are many people interested in buying TIPS, and while the value will fluctuate they can be exchanged for cash essentially instantly, for a minor transaction cost, at any point in the future. Your security is illiquid -- the number of people who would considering buying it is low, the number of people who would consider buying it from an existing holder is negligible, and the transaction costs associated with it are high.

TIPS have essentially no regulatory risk and have a built-in support infrastructure. Your security has significant risk that the contract will be unenforceable against you when you tire of your indentured servitude in 15 years (or 15 weeks), and no built-in infrastructure to make the guarantee anyhow. My accountant has no clue how to treat your security, but he is willing to investigate the matter at about $300 an hour. Hopefully he will tell me "WTF are you thinking, no, just no" early rather than running the clock out, if not, that comes directly out of my investment returns.

The details of your agreement are not fleshed out. This is presumably because the idea has not passed the napkin stage: that should tell you something. Let's see, does this cover investment income? Does this cover equity stakes you may receive in companies you found, and/or receive in return for services rendered? If so, does that 3% accrue immediately or at liquidation of the stake? Are you obligated to liquidate it at a timing preferable to the person holding the equity stake in you?

Do you smoke? Sorry for prying, had to ask to get a good picture of how to value this security. Can I sue you if you start smoking? I mean, I'm not an actuary (I'll have to hire one -- drats, more costs), but I'm pretty sure if you start smoking you probably cost yourself somewhere north of six figures of income, and since 3% of that is mine, you're essentially stealing from me.

Your proposal doesn't make much sense for charitable reasons, either. I like charity, but I do not consider all charities to be created equal, and most donors are like me (with different preference sets, granted). For example, when I think charity, I might think feeding the hungry or educating poor kids or supporting veterans. You might hypothetically think abortion clinics. That would be deeply problematic to me. I don't really have that risk if I direct my donor dollars.