[LetsHugItOut]

Some quick clarifications:

-- Yes, all 4 options you listed are possible. You could also, of course, quite easily combine options 1 and 2 or 3 and 4 -- that is, open a single account and invest both in funds managed by that firm and funds not managed by that firm. (And nothing is stopping you from opening accounts at multiple firms if you'd like to do that for any reason!)

-- Any brokerage that you have an account with will ultimately do what you tell them to do with your money. So while Merrill might offer more guidance than Fidelity and certainly ETrade, you would of course still have complete discretion over your money at Merrill. They probably don't have the same user-friendly online experience of Fidelity or ETrade, but online trading and account overseeing is still possible at all full-service brokerages I'm sure.

-- Again, Vanguard's brokerage is in a somewhat undefined spot between a full-service brokerage and an online brokerage. So while you could get some investment advice from them, this is not as much of a focus of theirs as it is for full-service brokerages or even Fidelity or Schwab (other firms in the middle, but leaning more towards full-service). FWIW, I opened accounts with Fidelity recently and sat down with an investment rep at a branch. His recommendations (all the company allowed him to do, I'm sure!) consisted of him walking me through basic literature that's available to the public (not just account holders) at fidelity.com. I'm sure advice would be no better at Vanguard. To receive better, more personalized advice from these firms, you would need larger accounts (at least $100K+). Or you could try a full-service broker, though these probably have basic account fees or minimums that Fido and Vanguard don't.

-- Finally, there are firms that are brokerages but not fund managers (I doubt ETrade, for example, manages its own index/mutual funds) and some that are fund managers but not brokerages (CAP Group is an example). Firms like Vanguard, T. Rowe, Fido, however, are strong fund managers and have brokerages ranging from adequate to great. I don't know enough to tell you where they all lie within this range, so you'll have to do some more research!