Technically it will work.
The main problem in keeping your funds with a hosted (shared) E-Wallet (like how most pool accounts and exchange accounts operate as) is that when you request a withdraw, you are at that service's mercy. If they have an empty hot wallet and need to transfer more funds from their cold wallet, you have no options other than to wait.
Instead, if you have the funds in your own wallet -- your transaction goes out immediately.
Additionally, let's say you were withdrawing to an address someone else gave you. If that other person happens to use the same E-Wallet service, then that transaction may not get broadcast to the network (i.e., is handled internally within the wallet as an account-to-account transfer). So you wouldn't have the blockchain as proof that you had sent payment.
So generally, you don't want to get in the habit of using your pool's withdraw feature as the method for sending bitcoins to other people.
+1