How to send imessages to non-iphone users on the macbook os x, if I don’t have an iphone

This is simple to accomplish if you have an iPhone to associate your phone number with your Apple ID account. I'm not aware of any way to hack, trick or cajole Apple to add a cell phone number to an Apple ID other than it going through the normal activation process on iPhone only.

1. Activate your Apple ID - http://support.apple.com/kb/TS4268
2. Open iMessage on the Mac and in preferences, set the caller ID to initiate messages from your phone number instead of your AppleID email.

As you can see, it is allowed to add more emails to an Apple ID, but the adding of phone numbers happens when you activate things from a live phone account and SMS messaging verifies that the phone number matches the iPhone.

Once that's done, Apple is happy to let your Mac or iPad or phone "iMessage" from that telephone number.

The only way you can do what you want is to turn off iMessage in each device that uses the same AppleID, where you do not wish it to receive iMessages associated with the AppleID.

I too share my AppleID with my family, but I share it so that there is a singular iTunes account where all devices can access the apps and music purchased on the shared account. (Family share does not work well).

The trick is have multiple AppleIDs. Dedicate one to iTunes, but then provide one for each user for iCloud. I don't want messages, photos, and other iCloud connected items to be shared, so the shared AppleID is used ONLY for iTunes. For iCloud uses, each person has their own AppleID, that they use for iCloud purposes. These family members do not use their own iCloud accounts for iTunes.

iTunes AppleID: all devices log into iTunes using this AppleID Personal AppleID: each device is logged into iCloud using a personal AppleID.