Having been on both sides of this, this looks strange.
I've never even heard of "exchangeable shares." I wonder what this is designed to protect against? An angel takes fewer protections but is also getting in a much more favorable price. Nor does the angel have any LPs to answer to.
5 person board is huge and unwieldy. Can you imagine how hard it will be to get 5 people organized for a board meeting?
I think a normal vesting schedule makes more sense, perhaps with double-trigger acceleration.
Right of first refusal will make future funding rounds hard, especially since the future round really ought to be priced by a new party. Typically, a prorata share is offered. This is very important in the event of a down round.
I wish I could have done my legal work for $6k. That doesn't smell likely to me.
On the number of directors, please keep in mind that this is at the time the angels have invested, so the company is reasonably far along. You must have an even number, so the choices are 3 or 5. Three is workable, but does not provide much diversity. If you can recruit good directors, five provides much better opportunty for CEO mentoring. Basil from www.AngelBlog.net