1. I mentioned this in your first post. Please stop SHOUTING!

2. You can leave that hard drive plugged in all the time. No need to remove it at all.

3. Depending on the size of this external hard drive, you should seriously consider using it, or a portion of it, as the Time Machine backup drive.
We would not want you to come back here shouting that you had lost/erased/damaged a file or app and were unable to continue with your projects without it.

4. An external drive will not do anything for your speed, it will just increase your storage space.