Trying to take off iMessage?

So my dad has an iPad and I have an iphone and my iMessage was linked to my moms email and my phone number and our iPads was linked to my moms email too. My dad just figured out how to turn it on so he can monitor my messages and it notified my phone when he turned it on. So I went to my settings and took the email off my iMessage so it's only linked on my phone number. Will all my messages still get sent to my dad's iPad? Also does it send the texts from people without an iphone to the iPad too?

Well its under his account so he still owns the account no matter what you do.

If you want your own then you need to signup for your own apple ID and not everyone sharing the same ID.

An IPad needs to use your email to use iMessage. It can be linked to a phone number afterwards. Messages to your iPhone may still get to your dad.
To remove your fathers access, you should completely turn off iMessage on both devices and remove the email and phone number from iMessage. Rumor is it takes 30 days once removed from iMessage truly remove device from previous lists.
Your dad will get a notification ( unfortunately). So he will know this has happened.

Consider using another App like text free.
Or
Can you change your email and password in iTunes to keep your dad out of the account? Do not make a new Apple ID, you must change the one you have.
I believe you have the option to block other users in iMessage. Dad will have to keep in touch via text.

Passcode lock your devices.
Learn how iCloud works and sign up online for it. This will allow you to remote lock either device or erase it if needed. Back up regularly.