Is this ECC encryption key sharing method okay?
To start things: Don't roll your own crypto.

What you're proposing is using standard static Diffie-Hellman for key-exchange, which by itself is a bad idea, as it will always result in the same key for each communcication between Alice and Bob. The key by itself should be safe, but as soon as it's broken all messages are as well. So if either the sender's public key is broken or the derived DH key is learned all communications are broken, whereas ECIES will still be safe (if the DH secret is learned one message is broken, if the public key is broken all messages to that person are broken and not all messages).

Next, ECIES provides authenticity and secrecy, meaning that if the message is altered in transit ECIES will output an error on decryption, using plain CTR + random IV doesn't provide this property.

So it's for these reasons (don't roll your own crypto, avoid static keys, think of authentication) that ECIES is the better choice.