The co-marketing clause is the one that should stop you. Putting another sponsor's offering in front of a list you only have because of a service contract looks like solicitation whatever the fee is called, and whether that triggers registration or broker-dealer issues depends on the specific facts of your arrangement, which means a securities attorney reads this before you sign anything.
On the fee, the distinction people rely on is whether your compensation varies with the sale of securities. An AUM fee doesn't have to. But AUM at this sponsor grows mainly when a new raise closes, so in practice your check moves with dollars raised, and that is the exact fact pattern to walk counsel through rather than reason about yourself.
Solder's analogy breaks on one point. A property manager's percentage of collected rent has nothing to do with securities laws, so it tells you nothing about how your fee gets characterized.
On data, one confidentiality sentence isn't enough. What you want is language naming the sponsor as the owner and controller of the investor records, you as processing them on the sponsor's instruction, admin access revoked within a stated number of days of termination, no retained copies beyond what you need for your own books, and a written wind-down where the sponsor gets a clean export and you get a signed receipt confirming deletion. State privacy laws differ on deletion duties and breach notification, so where these LPs actually live changes what you owe.
Two more things. Your E&O policy very likely excludes anything characterized as securities activity, so read the exclusions with the co-marketing clause next to you. And check whose name is on the portal contract itself. If the account is yours and an invoice goes unpaid, you're holding the sponsor's investors hostage, and that argument ends badly for the service provider every time.
