Is middlemans of equity legal?

I'm brainstorming with my self about a business idea, but I need more knowledge about that laws regarding equity.

Think about this scenario.

Person A owns 5,000 shares in a startup, no income yet. Can person A privately write an agreement with person B, that he will have access to dividends and profits in the event of an exit for the equivalent of 1000 shares? i.e. in the company's stock book, person A still stands as a shareholder and person B has no voting rights whatsoever.

In Sweden we have something called hembud (offer of first refusal?). Where other share holders have the right to buy shares that are sold before any new shareholder. This thing will bypass that.

What are the consequences, such as for tax purposes,

1. If the shares are given away without service in return (maybe to a child)?
2. If person B buys the right to the shares? Is this called something?
3. If person B shares the workload with person A. ie. Get shares instead of a money salary?

I'm interested in answers both regarding to Swedish (where I live) law or the law of the country you know.